If two laboratories report different results, the disagreement deserves investigation. It does not automatically identify which result is correct—or explain why the difference occurred.
Comparing methods against a shared challenge
NIST’s Cannabis Laboratory Quality Assurance Program, known as CannaQAP, was created to help laboratories evaluate measurement comparability and competence. Its Exercise 2 cannabinoid report, published in June 2024, examined measurements in plant material and allowed participating laboratories to assess their methods against community results and accepted values. Source: NIST Exercise 2 Cannabinoid Final Report.
Shared materials make a comparison more informative than unrelated reports from unrelated samples. A difference between two separate batches can reflect the material itself, whereas a coordinated study is designed to investigate measurement performance more directly.
Improvement is different from a public ranking
NIST explains that CannaQAP studies do not assign a pass/fail grade and that participating laboratories’ identities are anonymized in public reports. Its current program page also states that no additional CannaQAP exercises will be offered. The published findings remain available as scientific resources. Source: NIST cannabis laboratory quality assurance program.
It would therefore be misleading to turn an anonymous comparison into a ranking of named laboratories or to describe participation alone as a certification.
Report the unanswered questions
When discussing conflicting test results, separate the observed difference from the proposed explanation. “These results differ” is an observation. “One laboratory deliberately falsified its result” is a much stronger allegation requiring additional evidence.
Good quality reporting makes that boundary visible. It explains the comparison, describes what the study can establish, and leaves unresolved causes unresolved until there is evidence to support them.