Definition of Evidence-Based and Levels of Evidence

The Elementary and Secondary Education Act (ESEA) has consistently directed educators to implement interventions grounded in research. Under the new ESSA law, there is a shift to “evidence-based interventions”. This change is designed to help increase the impact of educational investments and effectively implement evidence-based interventions, which lead to desired outcomes, specifically an increase in academic achievement.

Evidence-based interventions are practices or programs that have evidence to show they are effective at producing results and improving outcomes when implemented. The kind of evidence described in ESSA has generally been produced through formal studies and research. Under ESSA, there are four tiers, or levels, of evidence:

Tier 1 – Strong Evidence: highest level of evidence
  • Supported by one or more well-designed and well-implemented randomized control experimental studies 
  • Intervention leads to favorable results

Tier 2 – Moderate Evidence:
  • Supported by one or more well-designed and well-implemented quasi-experimental studies
  • Controlled experiment was conducted with a treatment group 
  • Intervention shows statistically significant and positive effect on the outcome

Tier 3 – Promising Evidence: not as strong as evidence in an experiment
  • Supported by one or more well-designed and well-implemented correlational studies (with statistical controls for selection bias)
  • Formal study if a relationship exists between intervention and a given outcome 
  • Intervention shows a statistically significant and positive effect on the outcome

Tier 4 – Demonstrates a Rationale:
  • Practices that have a well-defined logic model or theory of action supported by research in the field 
  • Some efforts are underway by a state, district, or outside research organization to determine the effectiveness 
  • No formal evidence exists to prove interventions are successful 

Interventions applied under Title II, Part A may have evidence from tiers 1–4.

Please see the USDE Non-Regulatory Guidance for more information.


Contact:

Jennifer Wojcik
Coordinator of Professional Learning
Office: (410) 767-0346
jennifer.wojcik@maryland.gov

Sue Baile
Operational Coordinator
Office: (410) 767-0279
sue.baile@maryland.gov