Table 3.

Treatment effectiveness, effect sizes, and research strength by intervention characteristics

	Treatment effectiveness using PND*				Effect sizes using Cohen’s d*				Research strength**
	Very effective	Effective	Questionable	Not effective	Large	Medium	Small	Trivial or none	Strong	Adequate	Weak
Target skills
SE	6 (24%)	9 (36%)	5 (20%)	5 (20%)	2 (50%)	1 (25%)	0 (0%)	1 (25%)	6 (30%)	8 (40%)	6 (30%)
LC	5 (14.3%)	8 (22.9%)	9 (25.7%)	13 (37.1%)	3 (50%)	0 (0%)	1 (16.7%)	2 (33.3%)	9 (28%)	10 (31.3%)	13 (40.6%)
IP	3 (18.8%)	4 (25%)	1 (6.3%)	8 (50%)	0 (0%)	1 (100%)	0 (0%)	0 (0%)	3 (25%)	4 (33.3%)	5 (41.7%)
Modality
TH	2 (11.1%)	6 (33.3%)	3 (16.7%)	7 (38.9%)	1 (50%)	1 (50%)	0 (0%)	0 (0%)	4 (28.6%)	4 (28.6%)	6 (42.9%)
In situ	13 (21.3%)	16 (26.2%)	14 (23%)	18 (29.5%)	4 (40%)	1 (10%)	3 (30%)	2 (20%)	12 (30.8%)	14 (35.9%)	13 (33.3%)
Setting
Home	10 (25.6%)	10 (25.6%)	8 (20.5%)	11 (28.2%)	0 (0%)	1 (100%)	0 (0%)	0 (0%)	6 (33.3%)	6 (33.3%)	6 (33.3%)
Clinic	3 (18.8%)	5 (31.2%)	3 (18.8%)	5 (31.2%)	4 (50%)	0 (0%)	2 (25%)	2 (25%)	4 (26.7%)	7 (46.7%)	4 (26.7%)
Mixed	0 (0%)	1 (16.7%)	3 (50%)	2 (33.3%)	---	---	1 (100%)	---	2 (33.3%)	1 (16.7%)	3 (50%)
Dosage
Low	9 (22%)	7 (17.1%)	6 (14.6%)	19 (46.3%)	2 (66.7%)	0 (0%)	1 (33.3%)	0 (0%)	7 (33.3%)	6 (28.6%)	8 (38.1%)
Medium	2 (15.4%)	6 (46.2%)	3 (23.1%)	2 (15.4%)	3 (37.5%)	1 (12.5%)	2 (25%)	2 (25%)	5 (41.7%)	4 (33.3%)	3 (25%)
High	1 (16.7%)	2 (33.3%)	0 (0%)	3 (50%)	0 (0%)	1 (100%)	0 (0%)	0 (0%)	2 (28.6%)	2 (28.6%)	3 (50%)
Extended	0 (0%)	2 (66.7%)	1 (33.3%)	0 (0%)	---	---	---	---	1 (33.3%)	2 (66.7%)	0 (0%)

*N target skills classified by level of effectiveness (percentage of target skills classified by level of effectiveness)

**N articles classified by research strength (percentage of articles classified by research strength)

SE, social engagement; LC, language and communication; IP, imitation and play; TH, telehealth