There are many reasons to measure learning:
1. To assign learners with grades or give them a passing score.
2. To give learners feedback on their learning progress.
3. To give learners feedback to help them better understand the concepts being taught.
4. To provide instructors with feedback on learning.
5. To provide instructional designers/developers with feedback.
6. To provide organizational stakeholders with feedback.
7. To diagnose future learning needs.
8. To provide learners with additional retrieval practice (to support long-term retrieval).
9. To compare one learning intervention to an alternative one.
10. To examine the organizational impacts of learning.
11. To encourage learners to study.
12. To give successful assessment-takers a sense of accomplishment, a sense of being special, and/or a feeling of being in a privileged group.
13. To enable learners to earn credentials.
14. To increase the likelihood that the learning is implemented later.
15. To document legal or regulatory compliance.
16. To calculate return-on-investment of the learning program.
17. To collect data to sell or market the learning program.
Unfortunately, many of us don't recognize these as opportunities, or we confuse them, or we develop an evaluation instrument that is innapropriate for the reasons we say we're using it.
The other big problem in measuring learning is that most of us don't take human learning into account when we design our assessments. To learn more about that that, see my research-to-practice report, Measuring Learning Results...available at www.work-learning.com/catalog/.