People face trade-offs. This is part of the decision making process; when my alarm goes off in the morning I need to decide whether I will sleep in or eat breakfast, will I take a long shower or will I read the newspaper, will I brew a pot of coffee or will I buy a cup. Every choice I make comes with consequences of other choices that I cannot make. I took a promotion at work that requires me to work days, and now I can only take night classes at school. At work I have clients that face similar choices: if my study is worked by bilinguals then we will increase our chance of reaching the Hispanic demographic, but that will increase the cost of the study. When I was younger I was told that there are three ways that you can do things, and that you can only do them in combinations of two: quick, good, and cheap; if it is quick and good, it is not cheap; if it is cheap and quick, it is not good; if it is good and cheap, it is not quick.
People respond to incentives. There are times when we conduct studies that we would provide incentives to those that participate. This is much more common with professional studies, where we are asking someone who is at work to participate in a somewhat time-consuming study. If someone is working then they will not want to stop being compensated for work in order to not be compensated for their time, they are more likely to stop being compensated for work in exchange for being compensated for their time. There have been occasions