Table 5. Summary of the outcome of the hypothesis tests.

Hypothesis	Proposed relationship	Comment
H1	There is a positive relationship between interdisciplinary collaboration and:
	(a) measures of gender diversity	The more female members in the group, the greater the cited discipline diversity (Table 2).
	(b) the interdisciplinarity of the group	The more discipline diversity in a group, the greater the cited discipline and publication diversity (Table 2)
	(c) There is a negative relationship between interdisciplinary collaboration and the diversity of international membership	There is a negative relationship between publication diversity and the diversity of countries involved (Table 2)
H2	(a) There is a positive correlation between interdisciplinary collaboration in a group and number of publications.	There is a positive relationship between the number of publications and their disciplinary diversity and the diversity of the articles cited (Table 3).
	(b) There is an inverted-U relationship between interdisciplinary collaboration in a group and impact as measured by the median number of citations.	Median number of citations received by a group’s publications is highest for intermediate values of publication and citation diversity (Table 3 and Fig 2)
	(c) There is a positive correlation between interdisciplinary collaboration in a group and personal satisfaction	Respondents’ satisfaction with the group was positively related to the number of publications the group produced and the proportion of female members in the group, but negatively related to the diversity of the cited publications and the diversity of countries (Table 4).
	(d) There is a positive correlation between interdisciplinary collaboration in a group and perceived effectiveness	Perceived group effectiveness was negatively related to the diversity of the cited publications. It was, however, positively related to the disciplinary diversity of the group (Table 4)