Use when
- The task has two or more defined alternatives.
- Raw time, count, or visit data are available for each option.
- The denominator reflects the actual opportunity to sample each option.
Science Concepts
Science concept
Preference index
A preference index expresses relative allocation between options, usually as a normalized score rather than a raw count or duration.
Decision summary
Use a preference index when the question is comparative choice or allocation between alternatives. Report the denominator and raw component values so the index does not hide low exploration, side bias, or missing observations.
| Numerator | Difference, selected-option value, or target-option value. |
|---|---|
| Denominator | Total eligible observations across options. |
| Output | Ratio, percentage, or normalized index. |
| Audit field | Raw values for every option, not only the derived index. |
Do not use when
- Total exploration or observation time is too low to support a stable ratio.
- Side bias, order effects, or availability differences dominate the score.
Caveats
- The same index can come from very different raw behavior patterns.
- A strong preference score can be misleading when total sampling is low.
- Side, order, novelty, and sensory cues can shape preference independently of the intended construct.
Reporting checklist
- State the exact formula.
- Report raw values used in the numerator and denominator.
- Report minimum exploration or sampling criteria.
- State how ties, missing values, and zero denominators were handled.
- Report controls for side, order, and object or stimulus identity.
References
Willner 1984. The validity of animal models of depression.
Validity context for interpreting preference-derived behavioral readouts.
https://pubmed.ncbi.nlm.nih.gov/6429692/
ARRIVE 2.0 guidelines 2020.
Reporting expectations for transparent methods and outcome definitions.
https://pubmed.ncbi.nlm.nih.gov/32663219/
Related surfaces
Use these related surfaces to move from the scientific method question to the relevant product page, endpoint definition, analysis tool, or adjacent guide.
