What Do We Mean By Evidence-Based?

The Elementary and Secondary Education Act (ESEA), as amended by the Every Student Succeeds Act (ESSA), emphasizes the use of evidence-based activities, strategies, and interventions. Section 8101(21)(A) of the ESEA defines an evidence- based project component as being supported by four possible levels of evidence - strong evidence, moderate evidence, promising evidence, or evidence that demonstrates a rationale.

Strong evidence. To be supported by strong evidence, there must be at least one well-designed and well-implemented experimental study on the intervention.
Moderate evidence. To be supported by moderate evidence, there must be at least one well-designed and well-implemented quasi-experimental study on the intervention.
Promising evidence. To be supported by promising evidence, there must be at least one well-designed and well-implemented correlational study on the intervention.
Evidence that demonstrates a rationale. To demonstrate a rationale, the intervention should include a well-specified logic model that is informed by research or an evaluation that suggests how the intervention is likely to improve relevant outcomes. An effort to study the effects of the intervention must be planned or be underway.

Rigorous research evidence informs the National Center on Improving Literacy’s (NCIL) resources and recommendations about effective literacy approaches (i.e., activities, strategies, and interventions) for students with literacy-related disabilities, including dyslexia. However, not all approaches currently implemented by schools or districts have been rigorously evaluated. NCIL supports the implementation of approaches with the highest levels of evidence supported by rigorous evaluations.

SUGGESTED CITATION

National Center on Improving Literacy (2018). “What do we mean by evidence-based?”.

Washington, DC: U.S. Department of Education, Office of Elementary and Secondary

Education, Office of Special Education Programs, National Center on Improving

Literacy. Retrieved from http://improvingliteracy.org

REFERENCES

Non-Regulatory Guidance: Using Evidence to Strengthen Education Investments [PDF].

(2016, September 16). Washington, DC: US Department of Education. Retrieved from

https://www2.ed.gov/policy/elsec/leg/essa/guidanceuseseinvestment.pdf

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