Slide 1
Repeat under the same conditions
Measurement repeatability concerns agreement when the procedure, instrument and other stated conditions remain the same over a short period.
More to Read
Repeated readings help estimate short-term variation, but do not reveal every source of bias. A stable instrument offset can remain hidden in an otherwise tightly grouped sequence of results.
Slide 2
Change the conditions deliberately
Reproducibility concerns agreement under changed conditions, such as another laboratory or operator. The changed conditions must be specified.
More to Read
A test across operators answers a different question from a test across instruments. Reporting only that a result was reproducible hides which sources of variation were actually challenged.
Slide 3
Use references to connect laboratories
Shared reference materials and documented calibration chains help compare results. Their uncertainty remains part of the comparison.
More to Read
A disagreement can come from sample handling or method differences even when instruments share traceability. The entire measurement procedure, rather than just the equipment, must be examined.
Slide 4
Separate terminology across disciplines
Research fields sometimes use reproducibility and replication differently. A useful report describes the actual operations instead of relying on the label alone.
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Re-running one analysis on the same data tests computational consistency. Collecting new data with a comparable design tests additional parts of the research claim, so neither exercise can substitute for the other automatically.
Slide 5
Report enough to diagnose differences
Procedures, conditions and uncertainty estimates make comparisons interpretable. Agreement or disagreement without those details reveals much less.
More to Read
If two results differ by less than their combined uncertainty, the difference may not indicate a resolved conflict. Conversely, close agreement can still reflect a shared error, motivating genuinely independent methods.
Sources
- NIST TN 1297: Terminology
National Institute of Standards and Technology
- Metrological Traceability
National Institute of Standards and Technology