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Paul T. von Hippel
Multiply by 37 (or Divide by 0.023): A Surprisingly Accurate Rule of Thumb for Converting Effect Sizes from Standard Deviations to Percentile Points
Topics: MethodsTags: AssessmentEducational researchers often report effect sizes in standard deviation units (SD), but SD effects are hard to interpret. Effects are easier to interpret in percentile points, but converting SDs to percentile points involves a calculation that is not transparent to educational stakeholders. We… more →
Estimating Learning When Test Scores Are Missing: The Problem and Two Solutions
Topics: MethodsTags: Assessment, Learning environmentsLongitudinal studies can produce biased estimates of learning if children miss tests. In an application to summer learning, we illustrate how missing test scores can create an illusion of large summer learning gaps when true gaps are close to zero. We demonstrate two methods that reduce bias by… more →
Bias in kindergarten ability group placement: Does parental lobbying make it worse? Do formal assessments make it better?
Von Hippel & Cañedo (2021) reported that US kindergarten teachers placed girls, Asian-Americans, and children from families of high socioeconomic status (SES) into higher ability groups than their test scores alone would warrant. The results fit the view that teachers were biased.
Is kindergarten ability group placement biased? New data, new methods, new answers
Topics: Student LearningHalf of kindergarten teachers split children into higher and lower ability groups for reading or math. In national data, we predicted kindergarten ability group placement using linear and ordinal logistic regression with classroom fixed effects. In fall, test scores were the best predictors of… more →
How Much Does Teacher Quality Vary Across Teacher Preparation Programs? Reanalyses from Six States
Topics: MethodsAt least sixteen US states have taken steps toward holding teacher preparation programs (TPPs) accountable for teacher value-added to student test scores. Yet it is unclear whether teacher quality differences between TPPs are large enough to make an accountability system worthwhile. Several… more →
The data revolution comes to higher education: Identifying students at risk of dropout in Chile
Enrollment in higher education has risen dramatically in Latin America, especially in Chile. Yet graduation and persistence rates remain low. One way to improve graduation and persistence is to use data and analytics to identify students at risk of dropout, target interventions, and evaluate… more →
Year-Round School Calendars: Effects on Summer Learning, Achievement, Parents, Teachers, and Property Values
Year-round school calendars take the usual 175-180 instruction days of the school year and redistribute them, replacing the usual schedule – nine months on, three months off – with a more “balanced” schedule of short instruction periods alternating with shorter breaks across all four seasons of… more →
Does a successful randomized experiment lead to successful policy? Project Challenge and what happened in Tennessee after Project STAR
Topics: Policy, Politics, and GovernanceTags: School reform, Class sizeEvidence-based policy is the practice of basing policy decisions on rigorous research evidence, such as randomized experiments. But it is unclear how often evidence-based decisions produce more effective policy. We evaluate an evidence-based policy implemented in 1989-93, after the state of… more →
Does achievement rise fastest with school choice, school resources, or family resources? Chile from 2002 to 2013
Topics: Policy, Politics, and GovernanceDebates in education policy draw on different theories about how to raise children’s achievement. The school competition theory holds that achievement rises when families can choose among competing schools. The school resource theory holds that achievement rises with school… more →