What is Evidence?

The American Heritage Dictionary defines evidence as: “the data on which a judgment can be based or proof established.” Scientific evidence is the accumulation of data through evaluation and research that carefully examines how an intervention is delivered and what improvements result. Data is another word for numbers, as in the number of children that improve their functioning on a standardized measure, like the Child and Adolescent Functional Assessment Scale (CAFAS) or the number of families able to stay together and prevent out of home placement. Data can also be “qualitative,” as in narrative descriptions of families’ experiences in a particular program. It is important to use mental health treatments and therapies that have scientific evidence to prove they actually result in desired improvements and outcomes (e.g., a child’s aggression is reduced; child attends school regularly).

Researchers use many different types of designs and methods to study the effectiveness of interventions (does it work in helping my child and family?). A researcher can compare children who receive a new intervention with those that receive treatment as usual (called a comparison group). If children who receive the new intervention improve, the results are stronger because a comparison group was used. The results may also be stronger if the children were randomly assigned (by chance, as in flipping a coin) to receive either the new intervention or usual services. (For a description of different types of research designs see Understanding Research Designs.

If other researchers find the same positive results, this helps build a knowledge base about the effectiveness of certain interventions. Research results across many studies are typically reviewed and evaluated to determine whether the findings are strongly supported. This information helps us make decisions about which EBPs to add to our service systems.

However, other types of evidence are used to decide which treatments and services to use in our services systems. Families’ and practitioners’ observations of whether a particular intervention is working for them are also extremely important.

Helpful Links:

• The State of Oregon’s definition of evidence
• Hawaii’s Evidence-Based Practices Committee provides examples of how research studies are rated to assess EBPs in children’s mental health
• SAMHSA’s National Registry of Effective Programs and Practices rates programs on several criteria, including methods used in research studies that have tested interventions, whether instruction manuals are available detailing how the intervention should be delivered, whether they assess fidelity (e.g., how well the intervention was delivered compared to the instruction manual), and other criteria.