The effect of professional development on in-service STEM teachers’ self-efficacy: a meta-analysis of experimental studies

International Journal of STEM Education

Table 1 Sample sizes and study characteristics

Sample size
Number of included articles (pre-post and treatment–control)			21
Number of independent studies (TSE as outcome measure effect sizes)			48

Article publication information (n = 21)		# of articles	% of articles (%)
Publish status	Journal articles	13	62
Publish status	Unpublished manuscripts	8	38
Country	United States	14	67
Country	Other countries	6	33

Methodological features of the included studies (n = 48)		# of studies	% of studies (%)
Research design	Randomized controlled trial	24	50
Research design	Quasi-experimental	24	50
Grade level	Primary level	20	41
	Secondary level	19	40
	Mixed K-12	9	19