Online studies can create special problems, and the REP system has special policies for online studies. Some have to do with obtaining student names and IDs. Some have to do with technical problems arising from browser limitations or students who withdraw from a study without completing it or who do not seem to respond to questions in good faith.
1) When recruiting for online studies, use the REP function to "add/create seats." You can specify that this study has no time or place. Students can sign up for a "seat" and you can send the url for your study in their confirmation email (do not put the url in the description.) By creating seats, students have a record in their MyRep account, you obtain accurate x500s and don't overrun your allocation.
2) Occasionally, online studies involve very long questionnaires or require students to complete multiple questionnaires. Students have been known to log into a website, answer a few questions, and then...something happens. Either the student seems to withdraw quickly, without completing the questionnaire, or seems to blow through a complicated study so quickly that it seems impossible that the student has given any thought to their answers.
You suspect the student isn't answering in good faith, based on the validity checks or response sets that you have placed in your questionnaire. Errors like these may be the result of a bad attitude or the result of a weird browser. The REP policy is that students should be awarded points for participating regardless of the quality of the data.
3) PLEASE do NOT assume that students are trying to scam you or cheat you or email them to accuse them of trying to scam or cheat you. The participants in the REP program are volunteers, and they are not obliged to participate or complete your study. Please start with the assumption that the situation is affecting their behavior–that is, that something technical (the browser problem) or something about the design of your study (its length or complexity) is discouraging participation.
Online "no shows"
1) The false-positive situation.
Students may sign up for seats but fail to follow through on the study. You wonder whether you should create new "seats" to use your REP allocation (potentially over-running the allocation) or wait (potentially missing possible participants)?
We recommend that you specify a deadline (say, two weeks) by which students should have completed your study in your consent form. When that deadline passes, you can assume that the student has withdrawn from the study. Mark their status as No, excused, and 0 points, and create new seats. However, students may complete the study despite the deadline, and if this happens, award them points. The only risk is that you might overrun your allocation. Talk to the REP coordinator about getting supplemental points to cover these cases.
2) The unexpected guest situation: Sometimes participants may share the survey for your study with friends so you get data from someone who never signed up for the study. In this case, students who have completed the study without signing up for it should be awarded points, if possible. Contact the REP coordinator when in doubt about x500s.