Multiple sample results rows have the same max and resultCount values?

[dkedrowski]

Affects: PFAS Downstream Tracing, possibly others

Example query: Maine, Cumberland County, Manufacturing, 0-500

There are 18 result rows for Samples:

• Four have a Max of 30.7 and a resultCount of 12
• Thirteen have a Max of 44.7 and a resultCount of 114

It's unclear why there is such homogeneity in these results unless they are somehow duplicative of each other. If so, that's potentially misleading to users.

[dkedrowski]

I did a deep dive on this one, looking at both the results and the SPARQL query and believe I've found the main issue:

• ?sample coso:fromSamplePoint ?samplePoint;
• ?observation rdf:type coso:observedAtSamplePoint ?samplePoint;
• ?observation coso:hasResult ?res.
• ?res coso:measurementValue ?result_value;

The results come from observations that are not directly connected to samples. The result is a cross product between samples and results.

Here's a query at yasgui where you can choose one from four different samples. Each choice yields exactly the same query results because they are for observations at the sample point, not the sample itself (as near as I can tell).

Unfortunately, I'm not familiar enough with Contaminoso to suggest a fix.

[dkedrowski]

Possibly missing ?observation coso:analyzedSample ?sample to connect everything together