Psychology WA UFPR

Psychology WA UFPR

The quantitative study that I selected is an article by Villegas et al. entitled "Eyewitness memory for vehicles." In this particular study, researchers examined the proficiency of eyewitnesses to correctly identify the color and type of vehicle that would be used purportedly for some type of criminal activity. The study was based on the notion that eyewitness testimony is oftentimes inaccurate and mutable to a number of different factors. The findings widely supported such a hypothesis, with less than 25% of the subjects able to correctly identify the vehicle in question (Villegas et al., 2005, p. 27).

The qualitative study I selected to examine is by McQuiston-Surrett and Saks is entitled "The testimony of forensic identification science: what expert witnesses say and what fact-finders hear." In this study, the researchers cleverly manipulated the phrases that people listened to testimony from 'expert' witnesses to see if that would influence the listeners' decisions regarding the veracity of the eyewitness. As such, this study relied on qualitative means to find that the particular diction that witnesses used had a definite effect on the credibility with the fact-finders.

One of the principle differences related to these studies pertains to the fact that the former was quantitative and the latter was qualitative. Therefore, the former started out with a definite hypothesis that the researchers were attempting to prove and in fact did substantiate. The latter, however, provided a means for the researchers to gather evidence, after which they were able to come to a conclusion and a focal point for their study.

One of the key similarities in the design between these studies had to do with the fact that both articles were attempting to gauge the accuracy of witness claims. However, in the article by Villegas et al. The witnesses were the ones studied for accuracy, whereas tin the other article the witnesses were the ones who are able to present qualitative descriptions to influence the judgments of the listeners. There were some similarities in the study designs between the two articles for the simple fact that there were variations of choices that the respondents could choose from to elicit data. In the vehicle study, witnesses had to select from various types and colors of vehicles, four of the former and three of the latter. The variables in the study in which listeners heard from 'witness testimony included the participation of both jurors and judges in Arizona, five differently worded findings, as well as two versions of conclusions in which it was stated that the 'suspect' either did or did not commit the crime -- in the opinion of the expert (McQuiston-Surrett and Saks, 2009, p. 441).

However, the data collection was extremely different. In the vehicle witness study, the findings were simply the mathematical results of the percentages of the people who were correct in identifying the requisite vehicle. In the other study, researchers were able to determine how different phrasing and diction swayed the credibility of witness testimony -- with some of the phrasing even mentioning the circumscriptions of forensic-based evidence.