Abstract
The paper describes some suitable methods of educational research for determination of the gain of an activity, i.e. what students/participants of some course/activity learned during that. An accurate approach to measure gain is an usage of pre- and post- test, interview or questionnaire - the article briefly summarizes these methods.
There are often used concept tests/inventories which should reveal the misconceptions of tested students. Further, we introduce our plans on the translation of the Calculus Concept Inventory into Czech and the intention to use the described methods on study of gain in Science Centres.