Psychometric features of an assessment instrument with likert and dichotomous response formats.

OBJECTIVE

To assess the psychometric properties of a Likert-formatted assessment instrument after altering the responses to a dichotomous format.

DESIGN AND SAMPLE

This methodological study used a 15-item instrument to obtain data from 183 participants who responded in both Likert and dichotomous formats. Response sets from each format were compared.

MEASURES

Each response set underwent factor analysis, Kuder-Richardson 20, Cronbach's α coefficient, item-total correlation, and parallel form equivalence tests.

RESULTS

Factor loads of the instrument varied between .362 and .754 when responses were Likert-formatted and between .370 and .713 when responses were dichotomous. The Cronbach's α coefficient with Likert-formatted responses was .858; the Kuder-Richardson 20 coefficient of the dichotomous responses was .827. Parallel form equivalences were significant at the level of r = .753.

CONCLUSIONS

The instrument had valid results when either Likert or dichotomous responses were obtained.