EFFECTS OF ITEM CHARACTERISTICS ON PSYCHOMETRIC PROPERTIES OF FORCED CHOICE

Two studies examined the effects of indeterminate frequency modifiers, item length, and statement direction on response to forced choice scale items. A pilot study established relative intensities of nine adverbial modifiers. Study 1 (N = 320) showed no effect on item variances due to the treatments. Differences were found be-tween mean responses of short and long items as well as between positively and negatively stated items. Study 2 (N = 110) investi-gated effects on scale reliability and validity related to different in-tensity levels of modifiers. It is concluded that differential responses to items may not reflect differences in the behavior referenced by the items but rather observed differences in individual responses may be due to the mechanical, grammatical or delimitive characteristics of the items. THE construction of items for use in self-report attitudinal and per-sonality instruments requires a variety of skills. Behaviors known or postulated to be related to the construct to be assessed must be identi-fied. Situations allowing that behavior to manifest itself must then be created and presented to the respondent in such a manner as to elicit responses related to the behavior. Training, practice, creativity, and experience are, no doubt, all requisite characteristics of the successful item writer. It is the choice of particular words to be used in items that was of interest in the present study. Modifiers, specifically those ad-verbs purposefully vague and void of precise meaning (indeterminat