Strategies for Digital Dig
By Sandra Schloen, August 2017
After piloting the digital capture of all excavation data at Tell Keisan in 2016, several major projects in Turkey and Israel used OCHRE as the data management tool for their 2017 seasons. [This included Tel Shimron, Israel; Tell Tayinat, Turkey; Zincirli, Turkey.] Given what we have learned from the experiences of these projects, we provide these strategies for using OCHRE as the primary data management tool to capture and integrate all of the data generated by a large scale excavation. Note that these strategies easily scale down to smaller projects.
Before Leaving Home
Equipment-related
Purchase a laptop or tablet computer, one for each anticipated excavation-supervisor; that is, for each supervisor maintaining a set of “books” for a Square or Area.
We recommend a Windows system with a minimum configuration of 32-bit processor and 2 GB RAM, although a 64-bit processor with a minimum of 4 GB RAM would be better. Look for a bright screen, long battery life, and a solid frame, along with a protective carry case. A built-in camera for taking ad-hoc field photos is also a plus.
Purchase a barcode printer. We have used the Zebra model P4T at 3 projects with great success. Have spare batteries on hand and plenty of labels and ribbons.Test your label printing before leaving home. For more details on using barcoded label printing with the OCHRE system, see Using Barcode Labels with OCHRE.
Be sure to have plenty of plug adapters for the electric sockets appropriate to the country where you will be working.
Run updates on all your computers before leaving home – Windows updates, Java updates, and OCHRE updates.
Data-related
Designate an on-site Data Manager for the project team. Excavations have specialists for all sorts of analyses – pottery specialists, faunal specialist, botanists, geologists, conservators, illustrators, photographers (conventional and aerial), a GIS team. All of these specialists will be generating data, complementing the extensive data production by the field staff. Having a data manager, to oversee, provide training, and manage the data collection and integration processes, is crucial.
If you anticipate needing to use OCHRE offline in the field, apply through the OCHRE Data Service for a special “dataman” account. This account gives the data manager a fast-track into a designated OCHRE project in order to manage the offloading and syncing up of multiple offline sessions.
Add your project team members as Persons in the database so that their data contributions can be properly attributed – drawings attributed to the illustrator, photographs attributed to the photographer, the registrar’s observations attributed, field staff observations atttributed. We generally discourage anonymous contributions to a project’s data – give credit where credit is due. “The computer says...” is not an authoritative source!
For Persons contributing to the data colleciton, add User accounts. Give an appropriate level of access for the type of data being produced. For example a field supervisor will need Insert/Delete access to Locations & Objects; a photographer will need Insert/Delete access to Resources.
Enter “Initials” on the Person pane for each supervisor for printing on barcode labels (or design labels in such a way that there is room for the full name).
Establish naming conventions for the primary objects of excavation – stratigraphic loci/units, pottery pails/buckets/baskets/lots, registered items or small finds, pottery (registered or aggregate), faunal remains (registered or aggregate), etc.
Set up Predefinitions to establish how each of these types of data is to be captured, named, and described.
Revisit Predefinitions used in previous years to make sure there is nothing that needs to be updated.
We recommend using the “Default to current user”and “Default to current date” options to ensure attribution to the contributing user as the data is entered.
Consider using OCHRE’s special serial-number properties to assign unique numbers to items being generated in the case where uniquely-named items is important. If serial numbers are in use, reset these for the start of a new season if necessary, or make whatever adjustments might be necessary.
Investigate the use of auto-naming features to have OCHRE name such items automatically, based on your project’s naming conventions. OCHRE’s Derived Variables feature, used in conjunction with auto-labeling, can go a long way to reducing data entry and eliminating errors when assigning Names, Abbreviations and/or Codes (e.g. barcodes) to items.
Consider the use of Tabular Views for entering specialist’s data (pottery, faunal remains, botanicals, etc.)
Setup Resource hierarchies with appropriate FTP access credentials to activate the special photographer’s interface that makes it easy to import, link, thumbnail, and move to the server all of the images taken by the photographer(s).
Set up your Inventory hierarchies and locations using the Inventory-insert button on the top menu bar. Create a location/object for each physical space and container that will house objects. Objects get assigned to these locations by adding a “Move to” event with the appropriate Location linked in to the Location field on the event.
Inserting Inventory Items
Using OCHRE offline
We recommend that you create new Location & Objects hierarchies, one for each anticipated offline session for the current season, to minimize the amount of content that needs to be offloaded for each session.
Copy (Edit-Copy item, Edit-Paste item) outstanding items from previous years that will be needed for the current excavation (e.g. loci left opened from the past season) from the primary hierarchy to the new season-based hierarchy. The Copy option uses the same item in a new context; this ensures that the updates to the item will be reflected back into its original context.
Create a new observation on items copied in from previous seasons to represent the work of the current season. This observation should be attributed to the new supervisor and dated to the start of the current season. New items entered within existing items will need to be re-integrated at the end of the season.
Establish the spatial reference to be used by the project (e.g. a UTM coordinate system, or the like) and set up OCHRE’s Preferences and Map Options accordingly.
Create a basemap to cover the extent of the project’s excavation within the chosen coordinate system. Assign this as the default basemap on the Resource Inbox’s Map options. Find a reasonable balance between resolution, extent and file size for sharing/downloading.
Create local basemaps, one for each of the season-based excavation hierarchies created above, and attach these to the Map options of the hierarchies appropriately. Find a reasonable balance between resolution, extent and file size for sharing/downloading.
Make shapefiles, or appropriate run-time geodatabases, and georeferenced raster images available to OCHRE for presenting existing spatial information.
Make sure you have specified, for each User who is set up to have an offline session, to Include GEO content offline.
Review our Case Studies for examples of how OCHRE has been used successfully in the field at active, recent excavations.
Upon Arrival
Equipment-related
Check the Internet connection as soon as possible. Use fast.com or speedtest.net to check effective speeds. We have seen OCHRE plod along at speeds of 2-4 Mbps, and we have witnessed offline sessions created with less. But you should aim to average 10-20 Mbps in order to minimally service the needs of a large project. Explore your options and get the best Internet service your project can afford. It will increase productivity and reduce frustration overall.
If speeds are low, considering purchasing better service – the faster thebetter! Investing in good Internet access will pay off.
Perhaps a faster wired connection can be achieved over a wireless option, or perhaps better speeds can be achieved by upgrading from a basic plan.
Purchasing a cellular-modem and Internet plan from the local telephone provider may be a good option.
If project staff members wish to use OCHRE on their personal laptops, check that OCHRE is up-to-date or help install the upgrade.
Ongoing
Equipment-related
Monitor Internet availability and usage. Every project will benefit from having at least basic Internet access which allows OCHRE to check in with its master database periodically. This step is essential for managing the more complex needs of a large project.
Keep field computers and barcode printers as clean as possible and charged up on a daily basis. Do not leave this to chance. Ensure that someone is responsible for charging the battereies of the relevant equipment, or that each user is absolutely responsible for having his/her equipment charged for each day’s work session.
Check printer ribbons and labels periodically; keep spares onsite (or in a designated field bag) if practical. Blow out dust from the print head as needed.
Data-related
Train, train, and train. Try to phase in new groups of users according to the natural rhythm of the excavation progress.
Field staff will need to be trained on the naming conventions, data entry procedures, predefinition use, barcode printing protocols, and offline procedures.
As small finds start coming in, train the Registrar to complete the registration of items initiated in the field. Note that these items are already identified – named and barcoded – and that they present with a preliminary description and stub properties. Establish with the Registrar the use of Events to help manage workflow and inventory: To conserve, To photograph, To draw, Move to, etc.
Train the photographer(s) on the OCHRE interface to help make this process integrate smoothly with the data being collected.
As Pottery processing begins, train pottery staff in procedures for capturing “pottery readings” or whatever summary or special processing takes place throughout the excavation. As faunal remains processing begins, train specialists in data capture.
Work with the GEO/GIS team to integrate or produce top plans, integrate field/aerial photography, integrate shapefile drawings of units of excavation, capture (import or link as point shapefiles with attribute tables that can match to OCHRE items) elevations/point from the Total stations or similar equipment.
Move images to an appropriate server, if possible, where they can be backed up in the cloud, or ensure that local backups (e.g. on external hard drives) are being kept up to date.
Run queries periodically to check the quality of the data -- missing Descriptions, missing Links, data outliers, etc. The OCHRE Data Service can suggest a variety of ways to monitor data quality throughout the data capture process.
Once targeted users are trained and data capture methods are running smoothly, introduce more junior staff or assistants to the processes so that everyone can get an appreciation of the value of onsite digital data capture, and can get experience dealing with related issues and solutions.
Consider ways in which the OCHRE Data Service back home might be of service. While our projects are in the field we are on call, ready to help.
At Season’s End
Integrate special hierarchies that were created for the season’s offline sessions into the master hierarchies as appropriate. (Remember that items that were “Copy”-ied in are already up-to-date.) Watch for Notes/Links on the parent hierarchy or container items being careful to leave nothing behind.
Validate the paths/presence of all uploaded photos using the Validate Utility on the relevant Resource hierarchies. This will ensure that both high-resolution and thumbnailed images are available for all photos, and that no images slipped through the cracks (due to early mornings, slow Internet, or the crush of wrapping up).