Development and validation of a research instrument for measuring the presence of democratic school leadership characteristics

The main purpose of this article is to describe the process of development and validation of a research instrument for measuring the presence of democratic school leadership characteristics. The instrument has been developed and validated in the city of Zagreb and Zagreb County in Croatia in four phases: theoretical construction; expert validation (N= 6 experts); pilot research (N= 77 teachers); and instrument structure validation through the main research (N= 651 teachers). The expert validation and pilot research took place in 2018. The main research was conducted in January and February 2019. According to Carmines and Zeller (1979), the results of the factor analysis, which show that the instrument is measuring a single phenomenon, indicate that all four hypotheses have been fulfilled. More specifically, several aspects of the extracted (i.e. unrotated) factor matrix support the following four hypotheses: the (unrotated) factor matrix of all 32 items explains a total of 66.793% of the variance; subsequent components demonstrate the fairly equal proportions of the remaining variance except for a gradual decrease; all items have high factor loadings on the first component (from .603 to .861); and all items have higher loadings on the first than on the second component.