Our goal with this types of instructions is to put users into as real conditions as possible and make sure, that they will answer questions in the way they would answer them in real life in given situation and if they personally had given motivation.
During our pilot experiments we found out, that users were often not reading instructions or have not understand them well.
To make sure that the users will read the instructions we tried several modifications, from putting instructions in different forms (paper/display), moving they position on display, using different colors, different fonts etc. We achieved some improvements, but it was never close to 100 percent.
Another problem was understanding of instructions. Even if user have read instructions, often he would not understand them correctly. We have tried several modification of instructions that had the same meaning but were put in different words. And again, we had some improvements, but never close to 100 percent success.
Then at our weekly student seminar of PeWe group at FIIT STU I have put this problem forth to my colleagues and after discussion that lasted several minutes there came this simple solution, to ask user after instructions question about the instructions and not let them pass unless they answer correctly.
This was simple but efficient idea. After several times we arrived at simple similar process using question after instructions. After user has read instructions, we ask him to describe how he had understand them in his own words. We found out that after this simple question users had almost every time read and correctly understand instructions.
We think, that making user answer question after he has read the instructions has made him read instruction, and the way he has to answer it, in his own words, has made him think about the instruction and understand it properly.