(and the need for feedback)
Guessing can be a useful strategy. Students might not think they know the answer to a question, but they quite often know what it is not, allowing them to reduce the pool of possible options. In the case of multiple choice questions, the sight of the correct answer can trigger our knowledge of it. In studies of memory, so-called cued recall works better than simply having to recall cold, so to speak.
But there are problems with this strategy. Because we are wired to make connections between things and use cognitive schemata in order to organise our knowledge and understanding of the world, we often recall things that were never actually part of the original memory. If, for example, I ask you to memorise a list of words associated with sweetness (such as, sugar, chocolate, cake, candy, and so on) and I then asked you to recall these words, chances are you would recall a word that wasn’t on the list (sweet, for example).
In a classic study (Brewer and Treyens, 1981), students were shown an office containing a number of items and then asked to recall the items they saw. As well as the items that were in the office, participants also recalled items that weren’t there but were consistent with the office schema.
But what does this have to do with guessing?
These examples suggest that human memory can quite effortlessly recall things that never occurred and items on a list that, well, never appeared on the list. These memories become just as real as the actual memories. In the same way, an incorrect guess can be encoded as correct, even when the student has been alerted to the error.
Cognitive psychologist and world-renowned expert on eyewitness testimony, Elizabeth Loftus thinks guessing can be downright dangerous. In 1978 Loftus, along with Reid Hastie and Robert Landsman, found that when individuals are encouraged to guess on a test, their incorrect answer often crops up on a later test (Hastie et al., 1978).
Elizabeth Marsh and Henry Roediger (along with Robert and Elizabeth Bjork) also reached similar conclusions in their 2007 study, finding that when people make errors on multiple choice tests the errors can persist on later cued-recall tests (when participants are given ‘cues’ to help them recall previously seen material).
These and other research studies have led leading cognitive psychologists and experts on eyewitness testimony to suggest that guessing can be dangerous because when people guess, they might later recall their incorrect guesses as being correct. The problem, then, is one of memory; when people are forced to guess the answer on a test they often remember their guesses as being part of the original to be learned list, which perhaps explains why teachers continue to receive incorrect answers from students even when they have stressed that the answer they have given is wrong.
The role of feedback in ensuring errors don’t persist.
The problem with this, however, is that results can often be inconsistent. Other studies have identified the benefits of unsuccessful retrieval to learning. As long as the correct answer is, in the end, generated by the student or provided by the teacher then the error shouldn’t carry over to subsequent tests. Bridgid Finn found that when unsuccessful retrieval attempts were followed by feedback, long-term retention was better than when the correct answer was just given (Finn et al., 2012).
Feedback is, therefore, the key to ensuring the incorrect information is overwritten with the correct information.