“…The presence of an instructor was also very common among the experiments (36%) [18,19,30,46,55,93,96,98,116,180,192,193,223,229,230,254]. Less frequent production styles included handwriting (e.g., Khan-style, classroom-style videos) (16%), [93,136,190,204,209,223,230], talking-head (16%) [30,49,93,145,[190][191][192], screencasts (14%) [73,74,113,186,241,242], productions with virtual reality and 360-degree characteristics (14%) [11,33,47,84,100,175], and animations in videos (content created entirely with drawings, illustrations, or computer-generated effects) (14%) [6,42,145,170,205,…”