More on WARP Data (Part Two)

Yesterday, I wrote about “Densities and Visibility” and “Hidden Landscapes” with regard to the data generated by the Western Argolid Regional Project. Today, I am going to write up four more aspects of our virtual study season in what should be the final installment of WARP related writing this summer. (You can read the rest here, herehere, and here). 

Next week, I return to Cyprus (at least in my writing and reading), but for now, WARP is the place.

Here are the final four observations on the WARP data crunching season.  

3. Land Use. As part of our standard descriptions of each survey unit, we recorded a good bit of land use data. This includes things like dominant vegetation, evidence for recent plowing, and the presence of features such as terrace walls that indicate material investment in the landscape. We initially chose to record this kind of information to provide insights to artifact recovery rates, but we soon discovered that this data also provided a high resolution perspective on contemporary (and recent) land use in the Inachos valley. 

For example, it became clear from our data that three main commercial crops in the Inachos valley were olives, stone fruit (primarily apricots), and citrus. While olives are more or less ubiquitous throughout the survey area, citrus tend to only appear in units under 150 masl in elevation. Apricots appear in units under 200 masl leaving units of 250 masl and higher in elevation to olives. This likely has to do with the susceptibility of these crops to frost damage. The presence of windmill-like air circulators in the citrus fields to the northwest of Argos confirm that this territory receives some manageable frost during the winter months. More durable apricots, a major export crop in our survey area, can endure occasional frosts, but are less rugged than the ubiquitous Greek olive tree. 

Evidence for plowing tends to be most common at fields under 200 masl which have, for our survey area, moderate slopes of less than 13 degrees although fields with compacted soils that show some evidence for plowing in the recent past (which we call “plowed, compacted” soils) extend slightly higher in elevation (and average 215 masl) and with slightly greater slopes of an average of 14 degrees. Higher elevations and greater slopes than these tend not to see regular plowing and are characterized by unplowed field even when the erosion of soils on slopes exceeding 20 degrees creates loose soil conditions. It should come as little surprise that units with plowed and loose soils tend to have the highest artifact densities and the highest visibilities. It is worth noting, however, that units with plowed and compacted soils, which indicate recent, but not ongoing plowing, produced the higher densities than predicted by visibility alone. 

A significant network of terrace walls manage the sloping walls of the Inachos river valley, and we recorded over 850 units with terrace walls. This is over 10% of all survey units. The average elevation of a terraced field is 247 masl with no terraces appearing below 108 masl and the highest over 500 masl. The average slope of a terraced field was 26 degrees. Predictably, most of the higher terraced fields (over 245 masl) were not plowed and these tended to have steeper slopes. There were, however, a number of recently or currently plowed terraced fields at lower elevations and slightly lower slopes suggesting that access rather than elevation and slope alone determined whether terraced fields saw plowing. In fact, these recently or currently plowed terraced fields tended to produce much higher artifact densities than visibility alone would predict whereas unplowed terraced fields tended to perform closer to what one would expect based on their visibility. This almost certainly reflects the high artifact densities from fields surrounding the ancient acropolis of Orneai which is also in the immediate vicinity of the village of Lyrkeia and accessible via a network of paved and field roads.      

4. Describing Chronological Landscapes. Over the last week or so, the project directors have been thinking about how best to describe the distribution of material from various periods across the entire landscape. This is distinct from how we interpret or understand the historical significance of particular patterns in the landscape. Instead, the idea (to my mind) is to describe the distribution of material in a consistent way across the entire survey area that allows for at least basic comparisons.

On the most basic level we can compare the character of assemblages by number of artifacts alone, but this speaks very little to the distribution of artifacts across our survey area. Thus combining the number of artifacts with the area of the units in which they appear helps to give some sense of distribution. David Pettegrew in his recent (unpublished) analysis of the distribution of EKAS data used nearest neighbor analysis (based, I believed on the centroid of units) determine whether the pattern produced by artifacts from various periods is clustered or dispersed. The vagaries of artifact recovery patterns could, I imagine, be managed by comparison with the overall pattern of the survey which would allow us to say whether the overall distribution of artifacts from a particular period is more or less dispersed than the overall distribution of all artifacts from the survey (imagining that the latter reflects recovery rates). 

Obviously one challenge here is the differential visibility or diagnosticity of particular periods on the surface. Certain periods – such as Pettegrew famously argued for the Late Roman period in Greece – are more visible than others complicating a simple reading of distributional analysis as a measure for (say) the character of settlement in the survey area. The other challenge, of course, is the different date ranges for various periods which mean that comparing, say, the Late Roman period (which we date to AD300-AD700) tends to be a good bit longer than, say, the Classical period (450BC-300BC) which means that the Late Roman assemblage has had twice as long to develop in the landscape.

There are various ways to manage for the differential diagnosticity and the different length of various periods to make these assemblages comparable. I tend to be fairly pessimistic about the potential of comparing assemblages from different periods. In other words, I think it is pretty hard to make arguments for the expansion or contraction of settlement by comparing assemblages from two different periods unless one establishes that the material signature of the two periods is fundamentally comparable.

That said, I suspect that the distribution patterns of material from various period between different survey projects is likely to be more comparable than between periods in the same survey project. For example, issues of differential visibility or diagnosticity on the surface tend to be common to most survey projects in a region and in most cases periodization schemes are, if not absolutely the same, at least broadly consistent at a regional level. In other words, being able to describe the various period landscapes across the survey area serves as the basis for later analysis of the periods in question rather than the analysis, necessarily, of the survey area across time (although it should also inform how we understand the survey area diachronically).  

5. Chasing the Data. One thing that crunching data does reveal is the strengths and weakness of any dataset. Our dataset is quite a way from what I would consider big data and as a consequence little problems with our data can create big issues during analysis. (And here I’m assuming that the strength of big data schemes is that small imperfections or outliers in the data set tend be washed out by the scale of the data more generally, for better or worse). As I ran queries and did analyses and produced new datasets on the basis of data that we collected in the field, I discovered little problems. For example, the aoristic analysis that I posted last week was based on a chronology table that had the Archaic period dating from 750BC-AD450 rather than 750BC-450BC. This is meant that pottery dated to the Archaic period was rather significantly underrepresented in the aoristic analysis that I conducted. It is an easy enough fix, fortunately, one that probably would have become clear at some point in the publication process.

At the same time, doing the work of analyzing our material is part of what brings various limitations to our data to the fore. For example, we didn’t ask our field teams to record the presence of terrace walls. So I had to excavate this data from the a more general comment field. This was easy enough to do, of course, but I suspect that the dataset is a bit fuzzier around the edges than one generated by a simple check box. 

In the end, querying the data will both reveal its analytical limits and make it a stronger dataset. This kind of “slow data” work is both humbling, in that it reveals the limits of data collection processes in the field, and energizing in that it only through analysis do we recognize the potential of our data to reveal more about the landscape than we had intended.

6. Solitary Data Crunching. Finally, crunching data by myself has been pretty boring. One of the great things about study seasons is not so much the work of study, but the time to reflect, ask questions, make false starts, share processes, and think out loud (although my colleagues might not entirely agree about that last one!).

Crunching data alone in my home office feels so disconnected from the work of the survey. I’m left to my own devices and my own questions, I often end up spinning my wheels or working my way into a dead end of data which does neither speaks to whatever hypothesis that I have imagined nor leads me to new questions. 

When doing data crunching next to my (often much smarter) colleagues, however, I constantly encounter new ways of seeing the data and imagining how it speaks to the archaeological landscapes that we explored together. In that context, data oriented study seasons often led to trips through the survey area (and surrounding regions), shared memories and reflections on units and field practices, and deeper engagements with both the landscape and our data.

Data-ing alone, on the other hand, has made me feel not only a bit detached from the survey universe, but also mildly confounded by our data. Hopefully before we get to the publication stage, we’ll have time to revisit our data together in a more collaborative and conversational way, but for now, this is what we have and despite it being a bit uncomfortable, I think I’ve made a bit of progress. 

More on WARP Data (Part One)

As readers of this blog know, my colleagues and I on the Western Argolid Regional Project have been working our way through the data that the project produced over its three main field seasons. This (virtual) study season focused on producing some reports that would start to describe the survey area in general ways. These reports will help us in the future as we attempt to unpack the character of more specific artifact scatters and distribution patterns. They’ll also contribute to address some “big picture” questions in survey methods and methodologies. I’ve already blogged a bit on my work over the last few weeks (here, here, and here). This week’s installment will likely be my last and the most general.

Six things that I learned this WARP study season.

1. Densities and Visibility. Like most intensive surveys we counted the total number of sherds and tile fragments in each survey unit. These numbers alone don’t tell us much about the past, but they do provide insights into artifact recovery rates across the entire survey area. For example, we know that surface visibility and the quantity of artifacts in the plow zone are likely independent variables. The question then becomes whether the areas with higher artifact densities represent the quantity of material in the plow zone or simply zones where we have higher visibility (or geomorphological processes took place that revealed past surfaces). As I blogged about a few weeks ago, for our survey area lower visibility tended to mean lower densities in a fairly consistent way. This indicates that across the entire survey zone lower visibility areas are as likely to have significant quantities of artifacts as higher visibility areas (and vice versa). In other words, it suggests that the two variables are independent. We might see a different trend if the two variables were related. For example, if ancient settlements tended to appear more frequently in fields that were currently abandoned and overgrown, we might see unusual spikes in artifact densities at lower surface visibilities and lower densities – either proportionately or in absolute terms – with greater visibility.  

Another measure for this considers the variability of artifact densities at different levels of visibilities. A number of scholars have noted that as visibilities decrease our ability to consistently recover artifacts becomes more random. This may be the case in some environments, but at WARP, the variability present across visibilities (measured by the standard deviation divided by the mean) does not pattern consistently and if anything appears to slightly increase as visibility increases. 

VarVis

Background disturbance is another factor that archaeologists have recognized as impacting artifact recovery rates (as I’ve blogged about before). Background disturbance describes the amount of distracting material on the surface that complicates artifact recovery. In general, we did not notice background disturbance having a significant impact on artifact recovery rates at WARP in general. That said, when consider variability in artifact densities per visibility split out by background disturbance (which we recorded as light, moderate, and heavy) we can see that variability decreases with higher densities, but the pattern is not a particular strong one. It is telling, however, that variability increases with visibility in units with moderate and light artifact densities.

VarBGD

While the patterns here are not particularly compelling, I think they do hint at how background disturbances shape recovery rates even if the story they tell is not a dramatic one.

2. Hidden Landscapes. Survey archaeologist have long worried about hidden landscapes, a phrase coined by John Bintliff, Phil Howard and Anthony Snodgrass in an influential late 1999s article. While this article introduces a whole range of reasons for landscapes being hidden – from geomorphology to the fragility of ceramics fired at lower temperatures at certain periods – in crunching the WARP data, I concerned myself with just one or two factors. The main factor that I fretted about was the possibility that contemporary land use which shapes not only recovery rates (through factors like surface visibility and plowing; units that remain under cultivation, for example, tend to have better surface visibility and to receive the kind of attention that increases the amount of subsurface contexts visible to field walkers), but as importantly shaped access to fields. Overgrown fields, steep slopes or units inaccessible via field road, walking paths, or undergraduate clambering may well hide landscapes that survey projects could systematically overlook. At this point in our project, there is no chance of us going back to field to survey steep slopes or dense thickets of maquis, but we can look at the data to see if there are hints that certain periods were more common in certain kinds of fields or, better still, whether they appeared somehow out of sync with predominant densities across the survey area. Again, overall artifact densities do not necessarily suggest certain units saw more activity throughout the past than others, but suggest the happy confluence of field conditions and surface material.

To do this analysis, I ranked the units in our survey area by artifact density according to equal intervals. The lowest density unit was 1 and the highest was 5. I think looked at any period of under 1100 years (and these constitute “narrow” periods from WARP) and ordered them according to average density rank. The idea was to determine whether certain periods appeared consistently in fields where artifact recovery rates produced low densities. I recognize that this is not the only method to suss out whether certain periods were more hidden than others, but it offered at least a preliminary way to consider the problem at scale across our survey area.

For Bintliff and co. there was a thought that certain prehistoric periods might be hidden in their landscapes in Boeotia. On WARP, however, it appears that prehistoric periods – even rather narrow ones such as Late Helladic IIIA-B – tend to appear most consistently in units with the highest artifact densities suggesting the confluence of recovery rates and material in the plow zone revealed a significant assemblage of pre-historic material. Of course, this can’t tell us what we didn’t find, but it is suggestive when compared to material from the Medieval period, the Venetian/Ottoman period, and the Early Modern period. This material tended to appear in units with lower average densities and lower average visibilities suggesting that contemporary land use, access, and surface visibility might be working to obscure the Late Medieval and post-Medieval landscape in the survey area. The densely overgrown Medieval site near the village of Sterna which produced Late Medieval through Venetian material despite may be a useful example of an area where our survey might not consistently explore. The site stood above the highest cultivated fields in the Inachos valley and was densely overgrown in vines, trees, and weeds. Artifact densities was spotty owing to the difficult surface visibility and it seems probable that artifact densities if not otherwise compromised would have been significant. That said, the site near Sterna did produce some standing architecture, a series of (you guessed it!) cisterns, and stood at a strategic location where the Inachos river valley narrowed before opening out into the wider Lyrkeia valley. In other words, there are certain characteristics of the site that encouraged us to explore it in greater detail despite the limited visibility and challenging landscape. To my mind, this mitigates to some extent against the idea that the absence of certain landforms and situations have led to the underrepresentation of Late Medieval to Early Modern material, but this hypothesis will, of course, require greater testing.

Stay tuned for more tomorrow!

Three Things Thursday: Blogging, Archaeology and Climate, and Poetry

I’ve reached the point of the summer when all my projects seem to melt together into chaotic ball of deadlines, half-met expectations, and long bikes rides. Needless to say, it has not been very productive.

At the same time, I am having fun thinking about things to blog about and then stretching my morning blogging time well into my second cup of coffee. So this morning, I have three things that might, someday, mature into full blog posts.

Thing the First

Years ago (let’s say 2008), I wrote a piece on the archaeology of blogging (and blogging archaeology) for Archaeology magazine’s website. I returned to some of the ideas in that article with a piece co-written by Andrew Reinhard for Internet Archaeology which considered the place of blogs in the academic ecosystem.

Lately, I’ve been thinking about how blogging has changed over the past five years. When I started blogging, I imagined an audience who would be interested in understanding how the [academic] sausage was made. Along those lines, my blog would serve as part idea box, part academic scratch pad, and part preview channel for my various research interests. At my most optimistic, I considered it to be living supplement to my academic CV (with occasional dog photo!) and as a way to move back the veil on how academics produce new knowledge. In any event, it may be that this was an optimistic program from the start, but I continue to think that it has relevance. I suspect that this is even more true for today as the general public has become increasingly invested in understanding how scientific knowledge forms the basis for public policy, authority, and expertise.

That said, I can completely understand how my blog is not to everyone’s taste. Indeed, it seems like public scholarship has two main areas of emphasis. One is works that approach historical problems with a journalistic flair for narrative, description, and analysis. Ed Watt’s recent book on the fall of the Roman Republic fits this category as do works by the likes of Eric Cline or my colleague Eric Burin. These works have the potential to attract the elusive crossover audience that includes both academics and the general public and have emerged as a revenue stream for publishers and scholars alike. This is important at a time when library purchasing power is in decline and faculty salaries have tended to stagnate.

The other major strain in public scholarship, and one that has particular prominence in the blogging community, is politically engaged outreach. This involves writing — often for blogs, but also in more established publications — on both academic issues that have an impact on contemporary society and in efforts to demonstrate how the contemporary political discourse has had an impact on what we do as researchers. I find the work of folks like Sarah Bond, Rebecca Futo-Kennedy, and the folks who blog at places like Everyday Orientalism (and previously Eidolon) compelling and important voices. At the same time, I recognize that this kind of public outreach often puts you in the crosshairs of the political outrage machine on social media. On the other hand, their work also attracts significant positive attention from readers within and outside the academy and if the goal of public outreach is actually reaching the public, then these authors have succeeded in spades. 

That said, it is a very different kind of blogging than what I envisioned when I started my blog and one wonders whether the changing political and cultural economy of academia has fundamentally transformed the character of outreach and public oriented scholarship? 

Thing the Second

I really enjoyed this article in the Journal of Field Archaeology by Karim Alizadeh, M. Rouhollah Mohammadi, Sepideh Maziar, and Mohmmad Feizkhah titled: “The Islamic Conquest or Flooding? Sasanian Settlements and Irrigation Systems Collapse in Mughan, Iranian Azerbaijan.” It is another in the recent gaggle of articles interested in considering the role of climate change in the transformation of settlement and activity in the ancient Mediterranean (broadly construed) landscape. Alizadeh and colleagues look at evidence for fortifications and irrigation systems in the Mughan Steppe region of the Azerbaijan-Iranian borderland.

They argue that the Sassanians constructed a complex network of irrigation canals throughout the region that only faltered as a result of two major flooding events in the 7th century. These floods cut down the Aras River bed making disrupting its relationship to the steppe’s irrigation network. These flooding events may well be connected to changes in climate and hydrology precipitated by the Late Antique Little Ice Age. The subsequent abandonment of settlement in the Mughan Steppe in the late 7th century, then, may not be related to the Muslim Conquests and the arrival of Muslim military forces in the world. Or, alternately, the faltering irrigation may have made the regional less resilient in the face of political and military challenges. 

This kind of work has had me thinking more carefully about the settlement change in Greece in the 7th century and the relationship between climate change, changes in economic structures, and the evident reorganization of Greek rural settlement. While the data that we have for the environmental conditions at the local level remains fragmentary and inconclusive, comparisons with other regions of the Mediterranean give us another reason to resist assuming that political and military events precipitated changes in the settlement and economy.   

Thing the Third

Do go and check out the North Dakota Quarterly blog today. I’ve posted a poem by John Walser titled “Chronoscope 181: And that spot.” It’s a great example of how poetry (and music!) can do things with time that we struggle to accomplish in the more linear world of academic prose. Plus, it’s a perfect poem to read heading into midsummer and thinking about how long days can slow down time and make even the chaotic disorganization of summer feel like something significant… 

Comparing Assemblage Part 2

Yesterday, I introduced some of the work I’ve been doing with data from the Western Argolid Regional Project. I compared artifact assemblages from the same unit, but produced by two different methods: our standard survey field walking and more intensive 2 m radius total collection circles. 

As we have noted from similar experiments with the Pyla-Koutsopetria Archaeological Project, artifact densities produced by total collection circles tend to be significantly higher than those produced by standard survey. What remained less clear, however, is whether the larger number of artifacts recovered per square meter add significantly to what we know about the material on the surface or whether they mainly trade in redundant data.

More specifically, I was curious whether more intensive sampling of units with lower surface visibility might help us open a larger window into the assemblages present in the plow zone. This may seem more or less intuitive except that historically survey projects have tended to increase intensity in areas where more artifacts appear. Typically, projects employed more intensive collection strategies which ranged from gridded collection to total collection circles for areas designated as “sites.” 

To think about this, I compared pairs of units from the same area with different visibilities. For example, units 3420 and 3421 are from a large Roman site in the Lyrkeia Valley. Both units had above average artifact densities with 3420 having rather exceptional sherd densities (over 6000 sherds per hectare!) and the unit 3421 having high artifact densities (920 sherds per hectare). Unit 3421 has a visibility of 50% and unit 3420 was 80%. The areas selected for resurvey in both units had the visibility of 90%. They both had light background disturbance and compacted soils. The biggest difference between the two units is their size. 3420 is 2200 square meters and 3421 is smaller at 860 square meters. 

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The standard survey of 3420 produced 285 artifacts and the Resurvey 1 and 2 produced 83 and 115 respectively. The big spike in the standard survey line represents a gaggle of Early Roman amphora sherds turned up by the standard field walking. The slight hump in the blue line between 2600 BC and 2300 BC is from an EHII pithos sherd. Otherwise the profiles produced by the two types of survey are remarkable similar with the standard survey producing a bit more material datable to narrow periods.

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The results are largely the same from unit 3421. The most obvious difference, of course, is that Resurvey 2 produced 131 artifacts which is more than the 43 produced from standard survey and 79 from Resurvey 1. Despite the difference in quantity, the profiles is remarkably similar. Resurvey 1 recovered a small group of sherds of Bronze Age – Iron Age date leading to the orange line starting around 3200BC. The combination of material of Classical-Roman, Roman, and Late Roman dates recovered in Resurvey 2 produces the double-humped line that dominates this profile. The parallel, if lower lines, produced by the Resurvey 1 and Standard assemblages demonstrate that the increase in quantity adds little to the chronological range or distribution of material found in this unit.

Another case study produces somewhat different results. Comparing two units, 11027 and 11033 from the same area with lower visibilities, 40% and 30% respectively and slightly lower densities (which are nevertheless quite high for our survey area) of 207 sherds per hectare and 356 sherds per hectare respectively. 11027 has moderate background disturbance and 11033 has light and both have low vegetation and compacted soils. The biggest difference is unit size with 11027 being a positively massive unit for our survey at over 4800 square meters and 11033 being rather average with a size of 1684 square meters.

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The profiles produced by the various survey methods employed in unit 11027 are quite different. Standard survey produced an assemblage of 35 artifacts, while Resurvey 1 collected only 20. The assemblage from Resurvey 2, however, was 57 artifacts. The increase in material starting at around 1400 BC is driven by a single LHIII kitchen ware sherd and sustained by a robust, but rather undiagnostic collection of “Ancient Historic” (material dated to between 1050 BC and AD 700) semi-fine and kitchen wares that is paralleled at lower intensity by “Ancient Historic” material from Resurvey 2.  Both Resurvey 2 and Standard survey produced a spike in Late Roman and Roman utility and kitchen wares. Significantly, however, Resurvey 1 collected 3 sherds datable to the Archaic-Hellenistic period and material from these periods did not appear in the standard survey.

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Unit 11033 produced generally smaller assemblages with 23 sherds from Standard survey and 8 and 22 from Resurvey 1 and Resurvey 2 respectively. The major spike from Resurvey 1comes as a result of four semi-fine wares datable to the relatively narrow Early Roman period and is paralleled by a lower spike from the Standard survey. Resurvey 2 produced no other sherds datable to any period shorter than 1600 years! Resurvey 1 and the Standard survey produced some Classical-Hellenistic, Hellenistic-Roman, Roman, Late Roman, and as the late spike in blue shows, Medieval, Ottoman-Venetian material. The hump visible in the Resurvey 2 profile dating to around 450 BC represents a single Classical-Hellenistic fineware sherd and a collection of 13 semi-fine ware sherds dated to the rather broad Classical-Roman period. Despite the rather different profiles, then, the major patterns produced by diagnostic material are surprisingly similar between the two units.  

It is a bit tricky to generalize from two case studies, but the second pairing of units suggests that more intensive collection strategies when applied to units with low visibility but high artifact densities can produce additional chronological information from the units. In the first example in which visibility is higher, the Standard survey and resurvey profiles tend to be more similar.

Again, this is a very small case study, but it is suggestive that the traditional practice of increasing intensity in areas with high artifact densities (sometimes called “sites,” or euphemistically, “LOCAs” or “POSIs” or whatever) is less likely to produce new chronological information than a similar approach to units with lower surface visibility and correspondingly lower artifact densities. We did quite a bit of resurvey work in quite a few contexts across the WARP survey universe and by comparing the assemblages produced by different methods using Aoristic analysis, we should be able to test this hypothesis a good bit. 

It goes without saying that chronology is just one indicator of significance for artifacts collected over the course of survey. Variation in fabric, in function, and in shape also informs the analysis of surface assemblages and Aoristic analysis does not account for variation in these areas. At the same time, chronological continuity is the sine qua non for most analysis of survey material. If you can’t date material, then it is harder to make any historical arguments for it.

It is worth stating that this analysis is very preliminary and I am going to continue to tweak and firm up my formulas and the underlying data. And, we do plan on making all the data that supports this analysis available openly via Open Context

Comparing Assemblages

Over the last few weeks, I’ve been working with the data collected from the Western Argolid Research Project. Mostly this has involved going through the survey unit data that we collected as a way to determine general patterns of artifact recovery rates from across the survey area. This is important work, but largely unrewarding. I had run many of the queries on the fly while survey teams were still working in the field and had started to recognize the general patterns as they were emerging in the data. That said, it was still necessary to check things with the complete data set and I’ll post some more on this next week.

For today, I want to post on another aspect of my work with the WARP data. Over the three main field seasons, we conducted a series of revisits to our survey units to collect additional samples of material from the surface. Teams did this by collecting all artifacts in a circle with a 2 m radius from the survey units. We selected units for resurvey on the basis of location within the survey area, surface visibility, and artifact densities. 

These revisits had two main goals. First and foremost, we sought to use them to calibrate the assemblages produced through our standard survey methods where we collected density data and artifacts from a 20% sample of the surface through traditional field walking techniques. Secondly, we hoped that these total collection circles would also provide us with more robust samples from units where visibility, for example, compromised artifact collection.

I had started messing with this data in 2018 and made only a tiny bit of impressionistic progress. The biggest challenge for me was figuring out how to compare the three assemblages in a useful way. I discuss some of my difficulties here.

The biggest challenge was dealing with various chronologies that we assigned to our ceramics. The chronotype system allowed our ceramicists to assign a range of chronologies (and dates) to artifacts recovered in the survey. In some cases, these were immensely broad (e.g. “Ancient Historic” which has dates from 1050 BC to AD 700) and in some cases they were particularly narrow (e.g. Roman, Early which dates from 50 BC to 150 AD) and, in many cases, they were of more middling resolution (e.g. Roman which dates from 50 BC to AD 700). The different assemblages produced artifacts not only from different periods, but also from periods with different chronological resolutions. So answering the question whether more intensive collection strategies, such as total collection circles, produced different or just more material had to take into account the different resolutions at which we identified artifacts. In other words, we had to figure out whether recovering material dated to the “Early Roman” period in a resurvey circle mattered if we collected material datable to the broader, but inclusive “Roman” period in standard survey.

The solution to this problem was doing a little Aoristic analysis as a standardized way to represent the chronological profile of different assemblages. Aoristic analysis assumes that all artifacts have an equal chance of appearing in any year of a given chronological range. In other words, an artifact dated to the Roman period has an equal chance of appearing in any year between 50 BC and AD 700. Artifacts from more narrow period have greater values per year reflecting the increased likelihood that they would appear in any given year in the span. To complicate matters a bit, I also factored in the number of artifacts from any particular period. As a result, the charts that follow reflect not only the likelihood that an artifact dates to a particular year, but so the quantity of artifacts present in the assemblage with any probability of appearing in any particular year. I recognize that this is combining apples (that is probability of any artifact appearing in a year) and oranges (the quantity of artifacts present with various probabilities), but if we are using Aoristic analysis and its corresponding visualizations as a heuristic, then this kind of conflation is maybe a reasonable way to combine various kinds of data into one chart.  

Let’s look at some data. For the unit 2517, which is near the acropolis of Orneai and had 30% visibility, we did standard survey and two total collection circles. The standard survey produced 89 artifacts and the resurvey units produced 77 and 146 respectively. Despite the differences in quantity, the assemblages had rather similar profiles with the only exceptions being a bump in the Early Bronze Age generated by a small number of rather diagnostic EHI-II and EHI sherds. Resurvey 1 produced a Late Roman and an Early Medieval sherd which created the slight bump in the orange line. The presence of artifacts dated to the Archaic-Hellenistic period in Resurvey 2 created a more nuance profile in the centuries prior to the notable Classical-Hellenistic spike. The general similarities of the two profiles reflects the basic similarity between the three assemblages, but it is clear the material from resurvey did provide chronological nuance to the 

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Another unit from the same area, 4345, had three resurvey circles. Unlike unit 2517, it had higher visibility and a correspondingly more robust assemblage with 434 artifacts recovered during standard survey and 45, 173, and 68 recovered from three resurvey circles.

Similar to unit 2517, the basic profile of the assemblages appear the same, but the resurvey units do produce some notable spikes. Resurvey 2, for example, produced a single Late Helladic IIIA sherd. Resurvey 3, recovered 6 artifacts dating to the Archaic-Classical period and one Archaic sherd producing a narrower spike than the material dating to the Archaic-Hellenistic period recovered in the standard survey and in Resurvey 2. Resurvey 1 produce a single piece of Ottoman semi-fine ware which has a narrow 120 year date range and produced a late spike in the chart.   

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I have more case studies withs smaller assemblages that I’ll share later this week, but for now, this kind of visualization seems to be a useful way to compare groups of artifacts produced by different methods from the same units. What this will reveal about survey methods, both in general and in different circumstances, remains the question that more analysis will hopefully answer!

WARP 2021 Study Season

The 2021 WARP study season starts tomorrow. This means three things.

First, it means DATA. Like many contemporary archaeological projects and certainly most contemporary surveys, WARP produced a ton of data from its four seasons in the field and three study seasons. Despite spending some quality time with this data each year, it remained a bit provisional as our finds data was refined and updated and our survey unit data was polished. Moreover, as we digitize and analyze maps, we continue to produce more data that can inform our larger analysis. In short, this means a season of sitting in front of my laptop and crunching numbers.

Our biggest goals this season is to determine the main factors that impact artifact recovery rates from our survey area and then attempt to determine whether the variables impact recovery rates in the same way for artifacts from every period. 

Second, it means DISPLACEMENT. Some of my fondest memories of archaeological work do not involve toiling in a trench or slogging through another field looking for sherds. They don’t even involving hiking up a mountain and the rush at “discovering” an undocumented or unpublished fortification. Some of my favorite memories of doing archaeological work involve sitting at my laptop in the tiny room underneath the Marinos house in Ancient Corinth, crunching EKAS data with David Pettegrew. I also have fond memories of working on Polis data on Cyprus while sitting in the Polis storerooms or in the main room of our little apartment in the village.

In both of these cases, we had the ability to go out the door and wander around the excavation area or go and check out a particular unit, situation, or view. I’ve never been one for aimless driving around or hiking or other random outdoorsy activity that I don’t perceive as having a clear goal in mind. I do enjoy, however, checking things out and revisiting sites or scrutinizing problems at a site or in the landscape. The dialogue between the data and sites and landscapes ensures that the data remain tied to experience. In fact, I often think of data that we take with us into the field (either in our minds or quite literally when we check a measurement or test a hypothesis) as embodied data. These data are data that blend seamlessly with the sites themselves.

Of course, this year, like last, we can’t do that. I’m feeling a distinct sense of displacement from the field and it reinforces my idea that data as data, set adrift from a sense of place, loses something significant. 

Finally, no study season can happen without DONUTS. Tomorrow is National Donut Day. My plan is to make a donut pilgrimage to Sandy’s Donuts in Fargo to mark the official start of the WARP study season. 

Small Rural Sites in Cyprus

This weekend I read Catherine Kearns’s and Anna Georgiadou’s recent article in the Journal of Field Archaeology (2021): “Rural Complexities: Comparative Investigations at Small Iron Age Sites in South-Central Cyprus.” The article is good for a number of reasons and should be added to any reading list on rural Mediterranean landscapes. If you have time (and are into that kind of thing), you should just go read it.

Without summarizing a fairly short article, Kearns and Georgiadou report on their work at two rural sites which they documented using intensive survey, remote sensing (magnetometry and ground penetrating radar), and targeted excavation. But that’s not all! The site of Kalavasos-Vounaritashi was initially identified by the Vasilikos Valley Survey and the site of Maroni-Vournes by the Maroni-Vournes Archaeological Survey Project. The former took place in the 1970s and 1980s and the latter in the 1990s. Kearns and Georgiadou’s work, then, not only followed recent trends toward examining using more intensive methods small sites initially identified by archaeological survey  (perhaps best exemplified in the Roman Peasant Project) and also reflects a growing interest in rural landscapes defined by small (and sometimes ephemeral) scatters of ceramics. 

Both sites stand in the territory of the city of Amathus in valley that connected copper ore producing area of the Troodos Mountains to the sea and also provided access to timber, gypsum, and undoubtedly agriculturally productive area upon which the city and local communities could draw. These rural sites, however, were not simply economic outposts of the urban center, but also defined regional religious landscapes with shrines, defensive landscapes with military installations, and transportation landscapes with routes and roads. For archaeologists, however, the challenge has been that these landscapes have largely been assumed rather than argued. Unpacking the function of sites in rural landscapes is a long standing challenge for archaeologists as short term or seasonal habitation, short lived religious sites, temporary or periodic fortified locations, and a wide range of small scale production sites can all produce surface assemblages of remarkably similar appearance. Moreover, many small scale rural activities are likely not to appear at all on the surface or blink on and off according to plough zone activity, erosion, and seasonal changes in visibility.

Work like that done by Kearns and Georgiadou plays a key role in not only understanding rural landscapes but also the relationship between surface and sub-surface material in the countryside. What was particularly valuable about this article is that that authors demonstrated how their methods – from survey to remote sensing – did not necessarily produce the kind of obvious correlations between the data collected from the surface and excavation results. In fact, the excavated remains were quite modest (and pretty reminiscent of the results from our first season of excavation on the height of Pyla-Vigla). It strikes me that this kind of transparency in the publication of problem-focused and methodological archaeological field work is pretty valuable.

Finally, the focus of this article on the Cypriot Iron Age reminds me that if I had to do it over again, I might have focused some of my research on this important transitional period on the island. The political coalescing of the Iron Age kingdoms, the changes in rural settlement and economy, and the role that sanctuaries and fortifications played in defining the these kingdoms’ territories offer a brilliant range of significant questions for archaeology. 

One last thing. As far as I can tell, this article also included the first reference to Katie Kearns’s book, which is listed as “in press” with Cambridge University Press. I’m looking forward to reading it:

Kearns, C. In press. The Rural Landscapes of Archaic Cyprus: An Archaeology of Environmental and Social Change. Cambridge: Cambridge University Press.

Good Practice in Survey Archaeology

Last week, I read and thoroughly enjoyed the massive multi-author article, “A guide to good practice in Mediterranean surface survey projects” in the most recent issue of the Journal of Greek Archaeology.

Not only does it represent the collaboration of a number of key figures in Mediterranean survey, but it also reflects their vast range of experiences in different situations, regions, and landscapes. It’s aim is to produce a sweeping guide to “good practice(s)” in the Mediterranean which both recognizes the limits to best practice rhetoric in archaeology and offers a series of well-considered recommendations for archaeologists starting or engaged in survey projects in the Mediterranean.

In the spirit of good practices, I thought that I would think with the article as part of an shared conversation as opposed to respond to it specifically. Here are five things I think that I thought after reading this article:

1. Institutions, Questions, Methods, Scale

One of the remarkable things about this article is the wide range of experiences among the authors. Their experiences in the Aegean, Near East, Italy, and elsewhere ensures that they recognize the wide range of institutions and traditions present across the Mediterranean. In fact, the Mediterranean is a famously fractured landscape defined by different topographies, different national archaeological laws, different institutions, and different professional discourses. Surveys that cross thousands of miles in the Near East are simply not possible in the Aegean for not only reasons of archaeological policy, but also owing to the landscape and the kinds of research questions Aegean archaeologists tend to ask. These questions, in turn, reflect the academic and institutional history of archaeological work in these places.

Issues of scale and intensity likewise reflect the kinds of questions that survey projects seek to answer as well as the kind of permits issued and the access to resources: funding, labor, infrastructure, et c. Intensive pedestrian surveys have invariably developed in different ways in different contexts. As a result the authors are wise thinking in terms of “good practices” rather than “best practices.”

2. Landscapes and Sites.

The article also got me thinking a bit about the tension between the concepts of landscape and sites. The latter typically reflects an interest in settlement patterns, functions, and hierarchies that demand careful highly detailed documentation of concentrations of artifacts in the field. The classic technique used for surveys with an interest in sites is gridded collection (and corresponding “off-site” scatters). And while we’ve moved away from “dots on the map,” it seems like many surveys still think in terms of sites and want proceed with the assumption that surface scatters represent archaeologically delimited places of human activity.

At the same time, there are surveys with an interest in landscapes which tend to be less distracted by sites and more interested in the distribution of artifacts throughout the survey area. Distributional survey often seeks to answer questions that require an a large regional assemblage of material to consider interregional connectivity, diachronic changes in material culture, and presence/absence of certain periods across large areas. As a rule, these projects give less weight to any particular cluster of material on the surface and use intensive sampling of the environment as a way to identify larger spatial or regional trends.  

Projects that focus on landscapes also tend to privilege the integrated character of survey areas and often seek to weave together geological, environmental, ethnographic, and historical data to reveal the diachronic complexity of lived space. While projects with an interest in sites have started to do this as well, of course, but there remains a tension between surveys focused on sites and those focused on landscapes. This tension is most visible as surveys with an interest in landscape, at their most ambitious, look to phenomenology as a way to think about the survey universe as lived space in the past and in the present.

The influence of phenomenology in the Mediterranean survey is pretty small and most Mediterranean surveys tend to be fundamentally processual in their methods and analysis. Even then, a landscape approach reflects a different view of the survey universe. My thinking on this matter has recently benefited from some conversations with my colleague David Pettegrew who introduced me to the idea that siteless surveys are susceptible to “deconstruction.”  The refusal to distinguish between on-site and off-site scatters has produced assemblages of artifacts that are susceptible to being pulled apart in various ways to reveal landscapes associated with different historical periods, different methods, and different processes.

3. Time and Chronology

Good practice also explores the tension between time and chronology in intensive survey analysis. Unlike stratigraphic excavation which can create its own context for relative dating, survey relies on existing chronologies and ranges of absolute dates for the analysis of surface assemblages. In most cases, however, the ranges of dates are still quite broad meaning that while artifacts might be contemporary in the technical sense of sharing a period, they are not simultaneous in the sense of existing at the same time in the survey area or sharing depositional or functional worlds. In other words, artifacts of Classical date on the Isthmus did not all enter the landscape at the same time or relate to one another, but may well represent trends that existed over nearly two centuries of activities.

This lack of precision in dating in survey pushes us to constantly assess the character of the sample collected from the surface or sites especially since the standard chronologies used in excavation and surveys tend to be irregular in duration. For example, the Classical period might represented fewer than 200 years while the Late Roman period might represent twice that and the Final Neolithic over one thousand of years.

Time and chronology get all the more complicated when considering that an object like a fortification wall or terrace might be visible and functional for a thousand years or more whereas this is less likely for an amphora sherd. At the same time, it is not uncommon for a 2000 year old roof tile to be used as chinking in a 19th century church or as part of an early 20th century oven. 

In short, we’ve only just started to think about how survey requires a fundamentally different view of time than we might rely upon to make sense of an excavation. 

4. Process

I still get excited by formation processes and intensive survey. To my mind, this is the place where questions of time and scale intersect. It seems to me that the main difference between site-based survey and siteless survey rests in our confidence in our understanding of the formation processes that shape surface assemblages. A confident approach argues that sites reflect past human activities which took place in a particular space, at a particular time, and for a particular purpose or function. A less confident approach argues that while we can’t necessarily isolate the processes that create a surface assemblage in any one place, we know that the artifacts that are visible in our survey universe represent past human activities broadly. In other words, the range of human and natural formation processes will tend to obfuscate any patterns that consistently reflect the distribution of functional spaces where activities associated with a particular moment or period in the past took place. Instead, we get a muddled and residual record of past activities that took place in the survey universe that will inconsistently resist our efforts to isolate particular depositional processes. This inconsistency means that we either need to only work at the smallest possible scale, which like excavation, can hope to isolate formation processes that produced a particular surface strata or at a scale sufficiently large to make the need to understand the variables at any one site inconsequential to diachronic and regional level research questions.   

This lack of confidence characteristic of siteless survey may appear to compromise the interpretative potential of intensive survey which continues to lean heavily on research questions derived from excavation and historical narratives that focus on sites, individuals, and events. At the same time, we’d argue that siteless survey pushes us to read the landscape in ways that make questions about whether artifacts entered a particular surface assemblage (or survey unit) as a result of manuring or low-intensity activities less important than what these artifacts tell us about past activities in the survey area a whole. This also means that we don’t have to get bound up in the difference between a single episode of high intensity activity (e.g. a high-density military camp occupied for a few weeks) or a long period of low intensity activity (e.g. a season settlement) that might produce similar scatters.

As this article show, understanding the limits of what we can say about formation processes and the surface assemblages remains central to understanding what arguments we can make at a regional scale. 

5. Procedure.

Finally, I’m getting more and more interested in field practices. That is procedure at the most basic level. I’ve been mulling over publishing a series of intensive survey manuals.

For example, last month, the Western Argolid Regional Survey (WARP) published its survey manual. I have a copy of the EKAS survey manual as well that I’m kind of itching to publish. A few years ago, I pulled together a little gaggle of archaeological manuals that were available online and put them up here.

I’d love to add some more to that list or talk with anyone interested in publishing their intensive survey manual perhaps in a volume with several manuals presented side-by-side.

Three Things Thursday: Fiction, Archaeology, and Reading

It’s a Thursday and just after the mid-point of the semester. Most years, the wheels start to come off about now, and I’m certainly feeling a greater sense of general urgency than I usually do. 

As a gesture to a rather frantic time, it feels right to do a little “Three Things Thursday” to clear the deck of wandering blog material that is bound to get caught up in the machinery of daily life and bring everything to a stop.

Thing The First

Last weekend, I read Don DeLillo’s new novel, The Silence. It’s short and like so much “Late DeLillo” atmospheric. It describes a world when all digital technology simply stops working and five people are forced to encounter life in a fundamentally different way. 

For archaeologists interested in issues of ontology, the book is short enough to be a “must read.”  As the five individuals lose their digital tools (and the digital tools that make the contemporary world possible), they lose part of themselves. The loss of their digital prosthetics leave them with phantom memories that bubble up through their consciousness suggesting that the disruption of digital technology is not enough to entirely divest ourselves of the imprint of our digital tools.

The book also engages with time in interesting ways (and here it seems to pick up where Point Omega, his 2010 novel leaves off. In Point Omega time alternately slows down and speeds up as the characters encounter existence through various modalities including the vastness of the desert, a slowed-down version of the film Psycho, and the structure of a haiku (which apparently give the novel its structure). In The Silence, time appears to stutter, lurch, and double back on itself. One character begins to recite Einstein, the other the fractured commentary on the Super Bowl, while another attempts to understand how they arrived in New York after crossing the Atlantic on a flight when all technology stopped. The staccato stratigraphy presented through DeLillo’s dialogue will be immediately recognizable to the archaeologist who is asked to make sense of the sequence of events (which are so often non-linear) as well as the definition of each object.

Thing the Second

I also enjoyed Anton Bonnier and Martin Finné’s recent article in Antiquity, “Climate variability and landscape dynamics in the Late Hellenistic and Roman north-eastern Peloponnese.” As readers of this blog know, I’ve become increasingly interested in historical climate change and they way in which changes in climate shaped past societies and their archaeological remains. Bonnier and Finné’s article consider climate proxies from three caves in the Peloponnesus and attempt to correlate this data with evidence from intensive pedestrian surveys in the Argolid and the Corinthia. Needless to say this is a messy project, but the results are suggestive.

They propose that a shift is visible away from land on hill slopes during the Late Hellenistic and Roman periods. They then suggest that there exist the political and economic explanations for this: the shift away from diversified agricultural strategies associated with the “family farm” toward less diverse practices associated with the supplying of urban centers with grain. They add to this explanation the possibility that the Late Hellenistic and Roman period was also notably drier than the Classical and Hellenistic era. As a result, more marginal fields on hill slopes with thinner soils that were less likely to retain moisture, for example, were abandoned for better and more erosionally stable fields on the valley bottoms. They make clear that climate change was not the primary driver of this putative shift, but could have been a contributing factor.   

Thing The Third

I’ve been thinking a bit about how we read in the 21st century. In my introductory level World History class, I’ve asked the students to engage in non-linear reading of the class’s open access history textbook. Instead of moving chapter to chapter, region to region, I’ve suggested that student use the search function and read across certain themes, ideas, phenomena, and situations. Searching for topics such as “joy,” “love,” and “anger” connects Confucius’s quip on the joys of a contemplative life, the joy of Buddhist nirvana, and the joy of a Classical Greek religious festival. Love brings together Chinese and ancient Egyptian love poetry. Anger connects the fate of kings, the wrath of deities, and daily life in the Levant. For me, this kind of reading is exciting and disorienting, but for my students, it’s frustrating. Without the coherence and context of narrative (preferably supported by a strong sense of progress!), history becomes a cacophony of unrelated events.

I spend far more time working as an editor and publisher these days than I do as a conventional researcher and writer. As a result, I often find my day defined by oddly juxtaposed texts. Snippets of emails, poetry, typeset text, and academic prose jostle with each other more attention. On some days, it’s deeply fatiguing mostly because like my students, I want to encounter some kind of pattern. I want to find that rhythm of meaning that comes from sustained reading of a single or related texts. In its place, I find jostling voices and snippets of conversation overheard at a crowded bar. On my best days, this feels more real than a tidy narrative or a scholarly argument. The orderly style, tone, and forensic detachment feel inadequate to represent the chaotic realities of everyday life. 

WARP Field Manual: A Manual for an Intensive Pedestrian Survey

Over the last month or so, I’ve been puttering around with the field manual from the Western Argolid Regional Project. This was an intensive pedestrian survey conducted in the Inachos River valley from 2014-2016 (with study seasons in from 2017-2019).

We produced a field manual that we then updated as the project went along. In an effort both to contribute to the small number of publicly available field manuals from field projects and to make our project a bit more transparent, we decided to tidy up our manual and make it available via tDAR.

Some of my long-time readers might remember that a few years ago, I was keen to formally publish as many field manuals as I could via The Digital Press at the University of North Dakota. We formally published on field manual, the iconic Corinth Excavations Archaeological Manual in 2017 and it has been a solid and consistent performer, download over 1000 times and used in any number of university and college classrooms. We also prepared a little archive of archaeological field manual and you can explore it a bit here.

This work generated some tepid interest in formally publishing field manuals, but nothing came of it. In fact, even my WARP colleagues were pretty ambivalent about publishing our manual. I did typeset the WARP manual together so that if someone wanted to publish it, they could. We also made it available under an open access CC-By license.

In any event, you can download the WARP manual here. It’ll be up in tDAR in the next week or so and I’ll share that link as well.

WARP COVER FINAL01