Original article: How to Measure Learnability of a User Interface
The learnability of a product tells us how fast users reach optimal behavior with that product. It is important to measure learnability for UIs that get used relatively frequently. A learnability study involves repeated measurements of the same participants completing the same task. The result of a learnability study is a learning curve that will uncover how many repetitions are needed in order for users to complete the task efficiently.
Even if you don’t conduct a complete learnability research project to plot the full learning curve, thinking about these concepts will help you make the trade-off decisions to design products that target your most important customers. ~ NN/g Group