Question

What is the experimental design in this example?

The hypothesis is that a person can name an aggressive word more quickly if it is preceded by a weapon word than if it word is preceded by a neutral word.

The study subjects were exposed to two types of prime words (weapon words and non-weapon words). They were also exposed to two types of target words (aggressive words and nonaggressive words). Each subject was given a total of 192 trials, 48 in each of the prime type and target type combinations. The means of the times in each of these four conditions were used as the dependent variables. Therefore, each subject provided four scores to the analysis.

The subjects were undergraduate students ranging in age between 18 and 24 years. They were told that the purpose of this study was to test reading ability of various words. On each of the 192 trials, a computer presented a priming stimulus word (either a weapon or non-weapon word) for 1.25 seconds, a blank screen for 0.5 seconds, and then a target word (aggressive or nonaggressive word). The experimenter instructed the subjects to read the first word to themselves and then to read the second word out loud as quickly as they could. The computer recorded reaction times

Every subject named both aggressive and non-aggressive words following both weapon and non-weapon "primes."

Answer 1

How participants are allocated to different conditions in an experiment is determined by experimental design. There are 3 types of experimental designs, independent measure/between groups, repeated measure/within group and matched pair. Here in this experiment we are using repeated measures which means same subjects are participating and completing the different condition of the experiment. Each condition of the independent variable is tested by the same group of people, therefore it is type of experimental design. The pro of using this type of design is it eliminates the individual difference, but cons are there performance might be affected but it can be solved with counterbalancing.