Official reports (eg Anderson, 1977) show the huge variation of results from DI sites in Project Follow through. Looking at sites that achieved at or above national norms & better than similarly disadvantaged groups outside the study: only 1 out of 16 DI sites did this for spelling, only 4/16 for reading & 5/16 for Maths.
This shows DI was not the success many claim & there should be discussion about why results varied so much.
Official reports (eg Anderson, 1977) show the huge variation of results from DI sites in Project Follow through. Looking at sites that achieved at or above national norms & better than similarly disadvantaged groups outside the study: only 1 out of 16 DI sites did this for spelling, only 4/16 for reading & 5/16 for Maths.
This shows DI was not the success many claim & there should be discussion about why results varied so much.