1. Overview of Research Evidence
Module Three
Overview of Research Evidence
In this module, we will provide a brief overview of the different types of research evidence that you may find in your quest to answer your COPES question.

2. Different Types of Research Evidence
Research evidence may include:
Intervention outcome studies
Case Studies
Program evaluations
Meta-analyses
Systematic reviews
….and not all evidence is created equal
Research evidence may come from a variety of sources. You may be most familiar with intervention outcome studies, program evaluations, or case studies, which you may have read in school or heard about at a conference. In each of these cases the results of a single study is presented. These studies are useful pieces of research evidence. However, reading, studying, and interpreting individual studies can be quite time consuming. Although many different studies may seek to answer the same question or test the same hypothesis, individual studies can vary tremendously in terms of quality, size, outcome measures, and sample characteristics.
More recently researchers have developed tools made to synthesize individual studies. These tools, which include meta analyses and systematic reviews, greatly reduce the time and effort required to understand research results in a particular area of inquiry. For example, 6 studies testing an intervention aimed at reducing the risk for teen pregnancy may be combined to get a better sense of the average effect of the intervention. You can also think of this in terms of sample size. One study may include only 50 individuals, but the combined sample may include over 500 teens. The more studies, and thus the more participants, that are included, the more confident we can feel in the results.
We will talk more about these different types of research evidence later in the training. For now, just keep in mind that studies such as meta-analyses and systematic reviews are particularly useful because they describe the results of multiple studies in a relatively efficient manner. In other words, they take a lot of the work involved in the process of searching for and synthesizing research out of the EBP process.