title: Psychometric features of an assessment instrument with likert and dichotomous response formats.
abstract: OBJECTIVE
  To assess the psychometric properties of a Likert-formatted assessment instrument after altering the responses to a dichotomous format.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
authors.affiliation: Nursing Department, Ataturk University Faculty of Health Sciences, Erzurum, Turkey.
authors.forename: Canturk
authors.initials: C
authors.lastname: Capik
authors.forename: Sebahat
authors.initials: S
authors.lastname: Gozum
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055088:Early Detection of Cancer; D005163:Factor Analysis, Statistical; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000523:psychology*; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
keywords: Likert; dichotomous; instrument; psychometric evaluation; scale