Research and evidence
Assessed universe
An assessed universe is the set of entities eligible for inclusion in a particular study. It establishes the boundary of any comparative result.
Research and evidence
A result is meaningful within its methodology. Match the research question, assessed universe and measurement period before making a comparison. These reference notes explain evaluation concepts; they do not add indicators, weights or thresholds to any published WCRC study.
15 reference guides
Research and evidence
Unit of assessment
The unit of assessment is the entity or activity to which a result applies. A person, brand, operating company and corporate group require different evidence.
Research and evidence
Measurement periods
A measurement period sets the dates covered by the underlying evidence. It is different from the date a report is designed, released or presented.
Research and evidence
Primary and secondary evidence
Primary evidence comes from an original record or direct source for a claim. Secondary material interprets or reports other evidence. Neither label removes the need to assess relevance.
Research and evidence
Self-reported information
Self-reported information is supplied by the entity or people being studied. It can be useful while still requiring attribution, checks and a clear account of its limits.
Research and evidence
Survey sample design
Sample design describes how people or entities are selected for a survey. It shapes which population the resulting responses can help describe.
Research and evidence
Survey response rates
A response rate describes participation relative to a defined set of invitations or eligible contacts. Its meaning depends on a clear denominator.
Research and evidence
Survey weighting
Weighting adjusts how responses contribute to estimates under a stated method. It can address selected imbalances, but cannot repair every weakness in recruitment or measurement.
Research and evidence
Comparability across studies
Results are comparable only to the extent that their definitions and methods support comparison. Similar-looking percentages can answer different questions.
Research and evidence
Composite scores and weights
A composite score combines several inputs under a defined rule. Weights express how much each input contributes, while the underlying measures still need interpretation.
Research and evidence
Thresholds and qualification
A threshold states the point at which a defined condition is met. It should be established and explained within the relevant methodology.
Research and evidence
Evidence confidence and uncertainty
Confidence describes how much support the available evidence gives a particular interpretation. It is different from how impressive a result appears.
Research and evidence
Independent assurance
Independent assurance is a defined engagement with a specified subject, scope and conclusion. It is not a synonym for general confidence or internal review.
Research and evidence
Research corrections and version history
A version history explains how a published record changed. It helps readers distinguish a corrected fact from a new edition or a changed method.
Research and evidence
Reading a methodology before a result
A methodology explains the question, evidence and rules behind a result. Reading it first helps prevent an attractive label from doing more work than the study supports.