The goal of this contribution is to present the creation and development of inquiry based optical experimental units of the Interactive Physics Laboratory at MFF UK for upper secondary students. Each unit is guided by a worksheet that leads the students to formulate hypotheses and prove their estimates.
These units have been tested several times and altered based on feedback, namely students' comments and coloured parts that were very problematic (red colour) and partially problematic (blue colour), lectors' observations and filled worksheets analysis.