Question: What is the purpose of tricking your particpants into your experiments?

Frank Soboczenski answered on 12 Mar 2013:

As I am trying to measure one specific thing in my studies I try to control as much as possible or exclude as much as possible from my experiments which could have an unwanted effect on my results. This means I cant tell my participants that I am, for example, looking for how many errors they make when using a device otherwise they know about this and some would try not to make erros or some would get more nervous. This can have a very distorting effect on the results. So I must always trick them so that they cant guess what I am actually looking for. 🙂