Of the three teams, the land surveyors decisively led in each of these categories.
Interns: To be fair, the students didn't receive the same level of management as the other groups. To be realistic, even if they had, they probably would have needed substantially more direction. They didn't understand the functions or typical locations of features they were collecting — since they've never even opened manholes, catch basins, or inlets before — nor were they able to clearly distinguish a maintenance hole from a water or gas valve. Their data was erratic, and because they didn't take pictures, we couldn't evaluate the correctness of attributes.
Engineering technicians: This group improved slowly but surely in all categories. However, their productivity rarely exceeded one-third the output of the land surveyors, and their data typically took three times longer to process because of missing data or mismatched pictures. One of the drawbacks of the GeoXH unit is that when downloading to shape file format, it changes the file name to the generic “DESCRIP.shp,” which opens up risks of writing over previous downloads. I couldn't trust the technicians to download the data without overriding files, as they routinely forgot to download their cameras and file the pictures using the proper date format — a constant source of frustration, since the data could not be checked in a timely manner without the pictures.
Land surveyors: Each surveyor raced up the learning curve and achieved a thorough understanding of the project — and each contributed improvements to in-the-field data-collection processes. Mind-numbingly systematic, even their errors tended to be methodical, making inaccuracies easier to catch and correct. More importantly, they maintained safety, high productivity, and high data quality even when working in rights of way, adverse weather conditions, and heavy traffic areas.
In my experience, surveyors' linear natures produce the highest-quality data results. In addition to this project, I have managed environmental assessment inventories that paired surveyors with biologists. Again, the biologist/surveyor assessment teams were more productive and their data was more complete and consistent than the biologist teams without surveyors. This was also the case when I managed an electrical equipment inventory that paired surveyors with electrical linemen to identify equipment on utility poles.
I hope decision-makers will appreciate the real advantages of using land surveyors, along with a skilled data manager, to plan and implement their asset inventory projects. Listening only to the conventional wisdom about asset inventories can create a lot of expensive, bad data.
— Karen Zollman is a project manager with Seattle Public Utilities.