effect, in psychology and sociology, is a cognitive bias that results in a subject recalling primary information presented better than information presented later on. For example, a subject who reads a sufficiently long list of words is more likely to remember words toward the beginning than words in the middle. Many researchers tried to explain this phenomenon through free recall [null tests]. Coluccia, Gamboz, and Brandimonte (2011) explain free recall as participants try to remember information without any prompting. In some experiments in the late 20th century it was noted that participants who knew that they were going to be tested on a list presented to them would rehearse items: as items were presented, the participants would repeat those items to themselves and as new items were presented, the participants would continue to rehearse previous items along with the newer items. It was demonstrated that the primacy effect had a greater influence on recall when there was more time between presentation of items so that participants would have a greater chance to rehearse previous (prime) items. Overt rehearsal was a technique that was meant to test participants' rehearsal patterns. In an experiment using this technique, participants were asked to recite out loud the items that come to mind. In this way, the experimenter was able to see that participants would repeat earlier items more than items in the middle of the list, thus rehearsing them more frequently and having a better recall of the prime items than the middle items later on. In another experiment, by Brodie and Murdock, the recency effect was found to be partially responsible for the primacy effect. In their experiment, they also used the overt-rehearsal technique and found that in addition to rehearsing earlier items more than later items, participants were rehearsing earlier items later on in the list. In this way, earlier items were closer to the test period by way of rehearsal and could be partially explained by the recency effect. In 2013, a study showed that primacy effect is also prominent in decision making based on experience in a repeated-choice paradigm, a learning process also known as operant conditioning. The authors showed that importance attached to the value of the first reward on subsequent behaviour, a phenomenon they denoted as outcome primacy. In another study, participants received one of two sentences. For example, one may be given "Steve is smart, diligent, critical,