itwbennett writes "In a recent article, Dr. Markus Jakobsson, a Principal Scientist at PARC, offers some tips on effectively running human-subject research studies on Amazon's Mechanical Turk. '...[B]enefits [include] very low experiment costs, quick turn-around rates, and relatively simple approvals from human subjects boards. But you have to be careful to avoid bias and error.' says Dr. Jakobsson. For example, in many situations subjects may be biased just from knowing that they are participating in a study, or by knowing the goals of a study. To avoid this bias, you need to 'convey a different task to your subject than what you are observing — essentially deceive them — to see how they react when faced with the situation of interest. Consider a study of user reactions to phishing sites. You may, for example, say that you are studying the common reaction to online e-commerce sites, and ask them to rate how helpful various sites are, with a free-text input field where they can add other observations. You first show them three or four legitimate websites, asking them to rate and describe them; then you show them a phishing site and do the same. Will they tell you that this is a site run by fraudsters? If they do, they noticed signs of fraud without you prompting them.'" The author also gives tips on avoiding cheaters, and determining how much to pay and when.