The problem as cognitive psychologist is to attempt to find out the mental model human beings use to control performance. Performance can be based on many different things such as coordination, problem solving, or memory. The model that was used in lab tests the short-term memory for specific items. The short-term memory is used in many performance related tasks such as numbers, dates, and names. The purpose of running this experiment is to test the process to which humans use their short-term memory and how short-term memory can be affected under adverse circumstances. The purpose of cognitive models of performance in general is not just to explain given set of data but it is also to explain the organization of the cognitive process and to give an explanation to the entire cognitive processing system. This experiment will take the test subject through four different steps which include: encoding, comparison, decision and response execution.
The experiment used in lab was referred to as the Serial Scanning Model. This model of memory first takes a given set of numbers on a computer screen called the "memory set" These numbers can vary in range and are given to the subject to observe for as long as they wish. When the subject is ready, they press a key and the "probe digit" flashes on the computer screen. The probe digit is a single number that is either in the memory set or not. The subject has to rely on his or her short-term memory to compare and then press a "yes" key if they believe it was or "no" if they believe it was not. Immediately when the probe digit flashes the response is timed. The probe digit only flashes and does not stay on the screen. Accuracy and response time are both measured. .
These results will tell the researcher very valuable things about short-term memory and how it is used. For example, this scanning model of short-term memory will give the researcher results on how the subject used there short-term memory in regards to encoding, comparison, decision and response time.