Translocation relative to range: A standardized index for effect intensity

Research output: Contribution to journalResearch articleContributedpeer-review

Abstract

A standardized index for effect intensity, the translocation relative to range (TRR), is discussed. TRR is defined as the difference between the expectations of an outcome under two conditions (the absolute increment) divided by the maximum possible amount for that difference. TRR measures the shift caused by a factor relative to the maximum possible magnitude of that shift. For binary outcomes, TRR simply equals the risk difference, also known as the inverse number needed to treat. TRR ranges from –1 to 1 but is – unlike a correlation coefficient – a measure for effect intensity, because it does not rely on variance parameters in a certain population as do effect size measures (e.g., correlations, Cohen's d). However, the use of TRR is restricted on outcomes with fixed and meaningful endpoints given, for instance, for meaningful psychological questionnaires or Likert scales. The use of TRR vs. Cohen's d is illustrated with three examples from Psychological Science 2006 (issues 5 through 8). It is argued that, whenever TRR applies, it should complement Cohen's d to avoid the problems related to the latter. In any case, the absolute increment should complement d.

Details

Original languageEnglish
Pages (from-to)132-138
Number of pages7
JournalMethodology : European journal of research methods for the behavioral and social sciences
Volume4
Issue number3
Publication statusPublished - Jan 2008
Peer-reviewedYes

External IDs

Scopus 69949102240

Keywords

Keywords

  • effect size, effect intensity, effect magnitude, effect measures, effect indices, meta studies