Key Coverage

Extended School Day Yields Mixed Results In Boston

Lengthening the day at dozens of Boston public schools has yielded mixed results, a Globe review has found, offering a cautionary tale as the city seeks to double the number of schools with extended learning time.

For many schools, a longer day has failed to dramatically boost academic achievement or did so only temporarily. The uneven results prompted school district officials to scrap the extra minutes at some schools and the state to pull funding or pursue receiverships at others.

But other schools have successfully used an extended day to boost MCAS scores or expand offerings in the arts and other electives.