Survey Units are Unique Like Snowflakes

I had a mini database meltdown on the first day of field work and data entry. The specific problem with the database mostly involved how we were using it (and the limits on the particular tool we chose to use), but it highlighted the relationship between the unit as space and the unit as a procedural unit in intensive pedestrian survey. To put this another way, we can only walk the same unit once, and we are thinking about how to make our database reflect this.

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We began the process of creating new unique number for each field by creating a value that reflected the space of the survey (keyed to a polygon in our GIS) and the procedure we used to walk the unit. We identified four procedures: standard survey, grab samples, resurvey, or unsurveyed (used to describe, for example, a fenced area or a unit that is too close to the edge of a sheer cliff). 

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As I thought about this unique identifier for each unit in our database (and in our analysis), I got to wonder whether we need to refine this identification of a unit more. For example, there is the slim possibility that we could resurvey a unit more than once. So perhaps we should use as our unique identifier the space of the unit, the procedure, and the team leader. After all, this would allow us to distinguish as unique, different engagements with the unit led by different individuals. Even this might not be enough. If we’ve learned anything from Big Al Ammerman, it’s that you can never walk the same survey unit twice. Maybe we need to make the unique identifier the unit number, procedure, team leader, and date. 

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This is all a good bit to think about on the first day in the field, especially when it was damp, overcast, and muddy. Maybe it was being out in the field, however, and away from the blue light of the computer screen that prompted me to think about how we imagine space. It could also be that I managed to help to screw up mapping a few units as I got my survey legs back. Nothing like real fields in a changing landscape to shade my understanding digital contexts.

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One Comment

  1. Richard Rothaus June 5, 2014 at 9:38 am

    Back in EKAS days I argued for a time stamps as unit and pottery collection identifiers (and lost the argument). Year-month-date-hr-min-sec is going to be unique, even across teams. Plus, they don’t have to be exact, just unique. It avoids the arbitrary nature of numbering systems and the associated duplicates and errors. Look at your watch, write down what you see, and you are done. No need to preassign unit numbers or team names. As a back up, throw on a second entry of a UTM Coord. Tertiary backup is collecting GPS tracking logs (this was not so doable back then).

    Back in the records I can link these numbers to the start and stop time of each unit survey form as an error check and attach the spatial information.

    I frequently use this now. I carry a GPS tracker, make sure the time on my camera is correct, and add spatial data when I get home. Sometimes I just take a photo of a notebook page rather than record spatial data in the notes.

    Downsides: numbers are long. It is too industrial and humanists chafe. Trying to go full digital multiplies errors. Getting a group of people to sync time on GPS and cameras (if you go that route) is nearly impossible, as is always collecting and archiving GPS logs.

    Reply

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