3.2 Soil interpretation tool

3.2.1 Aims of the interpretation tool

The SASSA interpretation tool provides 'answers' to common, context-specific queries. Currently the list of queries includes:

The aim is for the archaeologist to have on-site access to possible interpretations of the context being excavated. This enables the archaeologist to know the importance of recording features in the soil description such as stoniness, which is useful for interpretation of deposit origins, or sedimentary structures, which is useful for identifying depositional processes. It also enables archaeologists to understand the context and make them look for other features. For example, if the context turns out to be the 'natural' they may decide to stop excavating. Alternatively, if the context has evidence of in situ burning, they may look for other evidence such as a hearth structure or windbreak.

Planned queries for future development include:

3.2.2 Using the interpretation tool

The SASSA interpretation tool can be accessed directly from the field tool home page for quick non-context-specific soil analysis or from the context level of the soil description tool for context-specific soil analysis. This second option allows relevant data saved to that context to be imported directly into the decision tree.

Figure 14: Screenshots showing the sequential data entry interface of the interpretation tool

Figure 15: Screenshot showing the result score of the interpretation tool

At either level the user is presented sequentially with a series of questions and possible answers. The user cannot answer a question lower down the tree until this point is reached but it is possible to return to and edit the answer to questions higher up in the tree at any time. The sequential interface and structure of a typical decision tree is shown in Figure 14.

Once the tree is completed the user is presented with a score between 0 and 100 (Fig. 15). A score of 0 is a strong negative, 100 is a strong positive and 50 denotes no diagnosis, either because of insufficient information or conflicting evidence. The results are explained in more detail in a table. Perhaps more important than the final score are the links to information about how the interpretation was made, what other information might be looked for, confounding factors not accounted for by SASSA, and ideas for further field and laboratory tests either to confirm the findings or to take the analysis of the deposit further (Fig. 16). This follow-on information encourages SASSA users not to follow the decision tree blindly. Instead, the tool encourages users to examine and question their deposits differently.

Figure 16: Screenshot of the typical follow-on pages linked to the interpretation tool results section

Again, the development of an editor tool is planned to allow users to create their own decision trees suited to localised conditions or questions. With the involvement of an experienced geoarchaeologist, this could provide specific support with sampling as well as interpretation. A future development of the project could be to create a repository of decision trees and queries to extend the range of the SASSA interpretation tool.


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Last updated: Mon Dec 15 2008