The Cognitive Validity of the Script Concordance Test: A Processing Time Study

Abstract

Background: According to the theory on which the Script Concordance Test (SCT) is based, scripts contain expectations on features that are associated with each illness and about the range of values that are typical, atypical, or incompatible. Purpose: To document the construct validity of the SCT, we investigated the theory prediction that once a script is activated, new incoming information (e.g., additional clinical features) is processed faster if it is typical for that script than if it is atypical. If it is incompatible, processing time falls in between. Methods: We presented 2 groups of participants (30 fourth-year medical students and 30 full-time geriatricians) with 64 clinical vignettes (divided over 5 types of prevalent clinical presentations in geriatrics), each accompanied by a diagnostic hypothesis aimed to instantiate an appropriate script. Next, we presented a new finding, which could be typical, atypical, or incompatible given the hypothesis. Participants had to decide as quickly and accurately as possible whether the new finding increased, decreased, of did not affect the likelihood of the diagnostic hypothesis. We administered the test on a computer. The dependant variable was processing time. We analyzed data with a repeated measure 2 × 3 analysis of variance. Results: Typical information was processed faster than atypical and incompatible information (M = 10.6 sec vs. 19.2 sec and 16.4 sec, respectively; p lt;. 001 for both). Incompatible information was processed faster than atypical information (16.4 sec vs. 19.2; p <. 001). There was no significant difference between the groups of geriatricians and students. Conclusion: It is possible to predict what kind of information will be processed faster depending of the typicality and compatibility of clinical data for given hypotheses. Results support SCT construct validity.