Online testing presents new challenges for teachers; notably, how to prevent students from cheating.  While cheating is problematic in a conventional classroom, the anonymity of the online environment and the lack of supervision makes it easier for students to attempt to cheat during online exams. Since most online evaluations are meant to be taken at home, students can have many alternatives for cheating. Fortunately, you can make these strategies more trouble than they are worth to the students.

Using Textbooks

The most common way for students to cheat is by looking up the answer in a textbook. The single most effective strategy for eliminating it is to assign time-limits on tests. A timed evaluation requires students to answer the questions in a certain amount of time. If the time-period is aggressive enough, students won’t have time to look up all the answers. On average, you should allow 30 seconds per multiple-choice question and 15 seconds per true or false question. Essay-type questions should be timed based on the complexity of the topic and the expected length of the answer.

Asking students to apply their knowledge to a unique situation not covered in their textbook is also effective. Application questions can’t be looked up. Students truly have to understand the material in order to properly answer the question. While they may take the time to read the textbook, they will still need to truly understand what they’ve read in order to successfully answer the question.

Working with Classmates

If students know each other, they may get together (offline or online) and try to take the test together. To eliminate this problem, randomize both the questions and answers on your quiz. Additionally, only select a subset of questions from a larger bank. Presenting different screens to the students makes it very difficult for them to cheat. This strategy coupled with a timed quiz makes it virtually impossible.

Printing Questions and Answers

Assume that students will print the questions. If you also provide the answer to these questions (after the test is submitted of course!), also assume students will print the results. To reduce the effectiveness of this cheating method, follow the same recommendation as above. Randomize the order of your questions and answers and only present a subset of questions. If you're serious about preventing cheating, I recommend having 10 times as many questions in your bank as you will display on your test. If students can only print 10% of the questions at any time, they will need at least 10-20 different copies in order to put together a useful printout.

Additionally, configure the system so that each student can only take the test once. Assuming that (a) not everyone in the class is a cheater and (b) not all students know each other (which is typically true of online classes), it will be practically impossible for a few individuals to print all of the questions and answers.

Having Someone Else Take the Test

Students will sometimes pay classmates to take online evaluations for them. To eliminate current classmates from taking each other's test, only make them available for a short time. For example, you could require everyone take a 30-minute test within a 1-hour window. Since a 30-minute test usually takes 40 minutes to complete (by the time you log in, read the instructions, etc.), a single classmate will not have time to take 2 tests within the window.

To prevent former students from taking an exam, use once again the randomized question/answer strategy. If the former classmate hasn't taken the test in a few months and the questions/answers are different then those he/she last took, chances are this cheating strategy will not be successful.

To take it one step further (assuming all students live in a close geographic area), have the test in a computer lab and warn the students that the exam might be proctored, which means students need to show ID. Proctoring the exams even occasionally will discourage students from having someone else take the exam in their place.

Obviously, there are many strategies students can use to cheat, both online and offline. A few people will go to great lengths to cheat, but if you make it harder to cheat then to learn, most students will give up and simply study harder.