Science teachers' self-efficacy significantly increased after participating in a professional development program focused on integrated STEM instruction, particularly after implementing the learned concepts in their classrooms. However, engineering technology teachers did not experience a similar boost, potentially due to pre-existing high confidence levels.

The study acknowledges funding from the National Science Foundation (NSF, award #DRL-1513248) but clarifies that the findings do not necessarily reflect the views of the NSF. No other conflicts were identified.

This study presents interesting findings on the impact of an integrated STEM professional development program on teacher self-efficacy. The Wilcoxon tests reveal significant improvement for science teachers, particularly after implementing their lessons. However, the significant methodological limitations, such as the small sample size, self-selection bias in the control group, reliance on self-reported data, and limited geographical scope, constrain the strength and generalizability of the findings, thus justifying an average rating of 3.