The "Follow Through project" was a huge US study of effectiveness of different approaches for dis-advantaged kids grades K-8.

In his article, "Project Follow Through: In-depth and Beyond," Gary Adams writes,

"The Follow Through project was the largest, most expensive educational experiment ever conducted. This federal program was originally designed to be a service-oriented project similar to Head Start. However, because of funding cutbacks the emphasis was shifted from service to program evaluation. Over 75,000 low income children in 170 communities were involved in this massive project designed to evaluate different approaches to educating economically disadvantaged students from kindergarten through grade 3"

"In fact, the Direct Instruction Model was the only model of the nine that had a positive cognitive score (and the results were extremely positive—over 35%). In contrast, students in two of the three cognitively-oriented models [TEEM and Cognitive Curriculum (High Scope)] had the lowest cognitive scores..."

"In contrast, all Basic Skills models had positive affective scores with the Direct Instruction model achieving the highest scores . The theory that an emphasis on basic skills instruction would have a negative impact on affective behavior is not supported by the data. Instead, it appears that the models that focused on an affective education not only had a negative impact on their students' basic skills and cognitive skills, but also on their affective skills."

"Perhaps the most disturbing aspect of the Follow Through results is the persistence of models that are based on what data confirms is whimsical theory .... The notion of the teacher being a facilitator and providing children with incidental teaching was used by the British infant school model (Open Education). It was a flagrant failure, ..."