Brief report: relative effectiveness of different home-based behavioral approaches to early teaching intervention.

Reed et al. (2007) compared two home-based ABA packages for preschoolers with autism. One group received 30 hours each week. The other got 12 hours.

Therapists used classic Lovaas drills and a CABAS style. Kids were tracked for one year.

The 30-hour group made bigger gains in IQ, language, and daily-living skills. Adding hours past 30 did not boost scores further.

In short, 30 hours beat 12, but 40 was no better than 30.

Linstead et al. (2017) later saw the same dose story in a larger sample. Their data still show more weekly hours speed learning, so the 2007 tip holds.

Slater et al. (2020) adds a twist. In an RCT, only toddlers with mild autism symptoms gained extra benefit when hours jumped from 15 to 25. Kids with severe symptoms improved the same at either dose. This extends Phil et al. by showing severity matters.

Samelson et al. (2026) seems to clash. In clinic records, kids who got the highest monthly hours actually progressed slower in adaptive skills. The gap is explained by setting: Phil’s families chose home programs and started young, while Doreen’s sample mixed ages and used community clinics where high hours can signal tougher cases.

You now have a clear hour target for home programs: aim for about 30 per week. Below that, progress lags. Above that, you burn budget without reward.

Always check the child’s symptom severity and the service setting before you lock the schedule.