Assessing the interdisciplinarity of a given body of research is an important work in bibliometric studies. Since the nature and concept of interdisciplinary is ambiguous and uncertain, various indicators have been created to capture interdisciplinarity. However, few studies have examined the consistency of these indicators. In this context, this paper aims to systematically explore and compare to what extent these interdisciplinarity measures are consistent, and observe which attributes of interdisciplinarity they aim to indicate. We examine these interdisciplinarity measures on WoS categories. Based on the Pearson's correlation coefficient, we find most measures in the different conceptual groups do not show high correlations. However, although measures in the same group are expected to be strongly related, some measures that are supposed to indicate the same attribute of interdisciplinarity are rather dissimilar. Furthermore, distribution figures provide an insight of the discriminatory power of the measures. Hence, we can identify measures with poor discriminatory power. In addition, we selected five WoS categories to carry out an in-depth analysis. These analyses are, to some extent, consistent with the Pearson's correlation coefficients. Our results provide some evidence that these measures indicate different attributes of interdisciplinarity, perhaps more than presumed.