What does the term "baseline data" signify in program evaluation?

Baseline data is foundational information collected before the implementation of a program, serving as a reference point for evaluation. It establishes the initial conditions, behaviors, or outcomes of the target population or subject area prior to any interventions. This is crucial for comparison purposes; when program activities are underway, evaluators can measure changes against this initial data, allowing them to assess the extent of impact or effectiveness of the program.

In the context of program evaluation, having reliable baseline data is essential for determining the causal effects of the program since it reflects the status prior to any interventions. Without this information, it would be challenging to ascertain whether observed changes are indeed due to the program or if they might have occurred independently over time. By collecting and analyzing this initial data, evaluators can paint a clearer picture of the program's success and overall impact.