Obtaining Baseline Data

When you launch a new program or initiative, it is important to record your baseline measurements so that you can track change over time. You should try to collect baseline data before a participant has experienced your program, but that may not always be possible. Here are some strategies for obtaining baseline data both before and after a participant takes part in your program.

Prospective: Collecting baseline data before a participant has taken part in your program

If you are collecting baseline data before a participant takes part in your offerings, make sure you provide enough time for them to respond before the start of your program. Use your logic model as a basis for defining the purpose and content of your survey questions, and use your planning period to prepare your survey. Remember: you need to use the same questions for the post-program survey to ensure that you can accurately measure the change in participants' responses. In order to analyze pre- and post-test data, you will need to use a specific statistical method called a paired-t test. Learn more.

Retrospective: Collecting baseline data after your program is completed

Sometimes collecting baseline data prior to the start of your program is too time-consuming, expensive or presents logistical challenges. Luckily, there are two methods you can use to obtain baseline data after participants take part in your program.

  • Post-then-pre collection:

    Once your program has ended, you can deploy a survey with questions about participants’ attitudes, behaviors and feelings both before and after the program.

  • Post collection:

    Once your program has ended, you can include questions in your post-program evaluation that illuminate the attitudinal or behavioral changes, if any, that have resulted from the program.


To what extent do you feel your participation in this program has changed your opinion about volunteering?

  • To a great extent
  • To some extent
  • To a small extent
  • Not at all

Compared to before the program, how has your opinion on the importance of volunteering changed?

  • Very much
  • Somewhat
  • A little
  • Not at all

If you plan to use retrospective baseline data to inform your programmatic decisions, there are important bias considerations to keep in mind as you analyze your data. Survey research has shown that respondents tend to underestimate change in their attitudes or behaviors when they are responding to a question after a recent experience—and, additionally, participants may feel the need to answer questions the way they hope the survey creators desire, rather than how they truly feel.

Retrospective baseline data can be a useful, convenient tool in measuring change over time, so long as you provide the appropriate context for how insights were derived when presenting your findings.