Professional beliefs is an important factor that influences activities that preschool teachers organize and manage in the classroom. In order to determine how strong these beliefs are, valid and reliable instruments must be at disposal. This research aimed to develop and validate DPBA, an instrument designed to measure teachers´ beliefs toward the use of inquiry-based activities in preschool classes. A sample of 1,004 Czech preschool teachers was used to obtain the validation data. From the initial set of 40 items, a final version of DPBA with 22 items was created in a series of analyses. Principal component and maximum likelihood methods with Varimax rotation were used to extract an appropriate scale structure. DPBA is composed of three subscales, Benefits (12 items), Teacher competence (6 items) and Concerns (4 items), which have reliabilities of .906; .847 and .729, respectively. The overall reliability of the instrument is .883. Consistently high reliability coefficients were obtained in subsamples of respondents of varied years of practice and education, thus verifying a solid internal consistency of the instrument. Confirmatory factor analysis proved a theoretical model with the three subscales with adequate model fit indices. Overall, DPBA possesses sound psychometric properties when used with Czech preschool teachers.
Keywords: inquiry-based activities, preschool teacher, instrument development, teacher beliefs.