The 21st century has brought a lot of change to the social sector. One of the most notable is the demand for measuring results. With this demand has come many new words — output, outcome, and impact. How are these measured, and how can you tell the difference? It can be confusing to many people. Here is a good, quick primer:
Output: Unit of measurement which counts; for example, individuals served or number of times an activity is conducted. It answers the question “what happened?”
Outcome: Unit of measurement which determines what has been accomplished; for example, as a result of the activity being delivered to the individuals served. It answers the question “what resulted?”
Impact: Unit of measurement which illustrates whether or not the service made a difference. It can be calculated by starting with the participant group outcomes (what resulted?) and subtracting control group outcomes (what would have resulted anyway?) from it. It answers the question “what difference was made? “
For example, an afterschool program has 15 seniors (output) in its program with the goal of increasing the graduation rate of its participants. It has a 95 percent graduation rate (outcome). If the target high school has a graduation rate of 80 percent, the program increased the graduation rate by 15 percentage points (assuming that the demographics of the student body and the program participants are constant).