Resources / General

Frequently Asked Questions

How do I know I can trust the Best Evidence Encyclopedia’s conclusions?

The Best Evidence Encyclopedia uses open, clear procedures that anyone could repeat. Most Best Evidence Encyclopedia reports are published in top journals in education, which means they are peer reviewed to make sure they are fair, accurate, and scientifically valid.

What defines an educational program?

For the purpose of the reviews in the Best Evidence Encyclopedia, an educational program is an organized, replicable approach to instruction.

Where can I find more detail on what the Best Evidence Encyclopedia says about each education program reviewed?

The full report contains details about each education program reviewed.

How can I locate someone to give a presentation about a program to our staff?

Contact information for programs is listed in the ratings tables.

How do I find out what schools or districts are using a program reviewed on the Best Evidence Encyclopedia?

Contact the name or website for the program listed in the ratings tables.

Will the Best Evidence Encyclopedia update reviews as new studies come out?

Yes, the Best Evidence Encyclopedia updates the topical reviews as important new studies are completed. The educator’s summary and the full report list the revision date of the review. To receive e-mail alerts of new reviews posted on the BEE and notices of upcoming reviews, sign up for updates.

How can I gauge the sustainability of a program?

In the full report, note whether a program has been the subject of a multi-year study. While this is not an assurance of long-term sustainability, it does suggest that a program has been used over a period of time.

Have any of the programs reviewed changed ratings over time?

Yes, it happens. Later studies can show results that change the ratings of a program. You may wish to visit the Best Evidence Encyclopedia periodically and check the revision date on the reports to see if a given rating has changed since your last use of it.

There are some programs that are not mentioned in the Best Evidence Encyclopedia reviews. Why is that?

The Best Evidence Encyclopedia lists programs identified through an extensive literature review. Each review lists programs for which there is evidence that meets the Best Evidence Encyclopedia standards as well as programs lacking any qualifying evidence. If you know of programs we have missed, please tell us about them. Contact

What are the minimum criteria for including a study in the Best Evidence Encyclopedia?

Studies must take place over a period of at least 12 weeks, compare a control group that has been matched to an experimental group, and use fair and reliable measures. Each full report contains a detailed description of the inclusion criteria.

How do reviews account for differences in state standards?

The reviews focus on comparisons between program and control groups being evaluated on the same standards.

How can we get buy-in from our school staff for use of research-proven programs?

If you’re sending teachers or other staff members out to look at programs, encourage them to start with programs that have strong evidence of effectiveness. For tips on overcoming obstacles to implementing research-proven programs, read the two-page brief below.

Do authors of the reviews on the Best Evidence Encyclopedia have a vested interest in any of the programs reviewed?

Some review authors divide their time between Johns Hopkins University and the nonprofit Success for All Foundation. Success for All Foundation programs are reviewed on the Best Evidence Encyclopedia. However, all programs are reviewed according to the same rigorous criteria in order to provide readers with a fair assessment. Most full reports have also been published in rigorous, peer-reviewed journals, which provide an outside check on the fairness and accuracy of the reports.

What is an effect size?

Effect size is a measure of the average difference between an experiment and a control group, as a proportion of a standard deviation. An effect size of +0.20 (20% of a standard deviation) is considered by the Best Evidence Encyclopedia (and others) to be a reasonable minimum effect size worth paying attention to.

What is the difference between statistical significance and effect size?

Statistical significance indicates the probability that the difference between the experimental group and the control group could have happened by chance. Effect size indicates the size of the difference, or the educational significance. A study showing positive effects of a program should indicate both statistical and educational significance.

How can I be sure a program with a high rating in the Best Evidence Encyclopedia will work with the particular demographic group our school serves?

The full reports usually describe the social class and ethnic makeup of the schools in which the research was done. You can see whether schools like yours have succeeded with a given program.

How can I be sure a program with a high rating will actually work in my school?

No program is magic. They all depend on high-quality implementation. However, it is very useful to know in advance which programs are likely to work if fully implemented.

How is the Best Evidence Encyclopedia funded?

The Best Evidence Encyclopedia is funded by grants from the US Department of Education and from the Bowland Charitable Trust in the UK.

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