Outliers: The Story of Success · chapter 9 · id outliers-c9-05-the-summer-slide-research-that

“The 'summer slide' research that Gladwell relies on -- primarily Alexander, Entwisle & Olson's Baltimore Beginning School Study -- used data from 790 children and found two-thirds of the ninth-grade reading achievement gap was traceable to differential summer learning in elementary school.”

needs contextconfidence: medium⚠ extracted by pipeline, re-audit pending

Receipts

Alexander, Entwisle & Olson (2007), American Sociological Review: Lasting Consequences of the Summer Learning Gappaywalled — manual check queued

Two-thirds of the ninth-grade reading achievement gap between lower and upper SES students was attributable to differences in summer learning experiences during elementary school.

Alexander et al. (2007), New Directions for Youth Developmentpaywalled — manual check queued

Using data from the Baltimore Beginning School Study, a representative random sample of 790 school children whose educational progress was monitored from first grade through age 22.

This claim is a stable, citable object. If you can falsify a verdict, tell us — corrections are loud here.