Specify Requirements and Classifiers for Selection - I

Having visualized whom you want to be vour from interna, sources about the groups, now try to think in terms of requin-.uc^ and Wass.user profile. Requ.rements describe what participants must come im^h

session knowing already. Classifiers he.r you put studv participant iltS categor.es (or groups) that may explain some effects you see in the E To make the concept of a user profile or user characterization more concrete you can take the traveler profile a bit further than the original visualization In this test, a participant must:

- Stay at a hotel a few times a year: We want people who would nor malty stay ,n a hotel rather than with friends or family or at a hostel, rather than a vacation home or time-share.

- Book some travel and accommodations online: Because this is an online reservation system, we want people who are familiar and com fortable with doing searches and credit card transactions on the web.

These are requirements. There's a temptation to get more specific What kinds of hotels do they stay in? How long are their stays? Which web sites do they use to make reservations through? But none of that really matters for selecting participants for this test, You can find out those interesting things later from a background questionnaire or in the session. Doing so may give you some context for analyzing the data from the test, but knowing these things ahead of time will not help you know why participants performed the

way they did with your reservation system. It may help to be more specific in the timeliness of the requirements — that is, participants should have done these things recently.