Does playing action video games provide more than just entertainment? The authors of the paper “Action-Video-Game Experience Alters the Spatial Resolution of Vision” (Psychological Science [2007]: 88–94) concluded that spatial resolution, an important aspect of vision, is improved by playing action video games. They based this conclusion on data from an experiment in which 32 volunteers who had not played action video games were “equally and randomly divided between the experimental and control groups.” Subjects in each group played a video game for 30 hours over a period of 6 weeks. Those in the experimental group played Unreal Tournament 2004, an action video game. Those in the control group played the game Tetris, a game that does not require the user to process multiple objects at once.
Explain why the random assignment to the two groups is an important aspect of this experiment.
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Introduction To Statistics And Data Analysis
- What is meant by the sample space of an experiment?arrow_forwardMcAllister et al. (2012) compared varsity football and hockey players with varsity athletes from noncontact sports to determine whether exposure to head impacts during one season have an effect on cognitive performance. In the study, tests of new learning performance were significantly poorer for the contact sport athletes compared to the noncontact sport athletes. The following table presents data similar to the results obtained in the study. Noncontact Athletes: 10, 8, 7, 9, 13, 7, 6, 12 Contact Athletes: 7, 4, 9, 3, 7, 6, 10, 2 a. Are the test scores significantly lower for the contact sport athletes than for the noncontact athletes? Use a one-tailed test with =.05 t-critical= t= b. Compute the value of (percentage of variance accounted for) for these data. r^2= a. 0.123, b. 0.239, c. 0.138, d. 0.264arrow_forwardIn a study examining the effect of humor on interpersonal attractions, McGee and Shevlin (2009) found that a man’s sense of humor had a significant effect on how he was perceived by women. In the study, female college students were given brief descriptions of a potential romantic partner and then rated the attractiveness of the male on a scale from 1 (low) to 7 (high). The fictitious male was described positively as being single, ambitious, and having good job prospects. In one condition, the description also said that he had a great sense of humor. The results showed that the description was rated significantly higher when “a sense of humor” was included. To examine this effect further, a researcher selected a sample of n = 16 college males and asked them to read a brief description of a female and then rate the attractiveness of the woman in the description. The description had been used in previous research but was modified by adding a statement describing a good sense of humor.…arrow_forward
- McAllister, et al. (2012) compared varsity football and hockey players with varsity athletes from noncontact sports to determine whether exposure to head impacts during one season have an effect on cognitive performance. In the study, tests of new learning performance were significantly poorer for the contact sport athletes compared to the noncontact sport athletes. The following table presents data similar to the results obtained in the study. Noncontact Athletes Contact Athletes 10 7 8 4 7 9 9 3 13 7 7 6 6 10 12 2 Are the neurological test scores significantly lower for the contact athletes than for the noncontact athletes in the control group? Use a one-tailed test with α = .05. Compute the value of r² (percentage of variance accounted for) for these data.arrow_forwardA group of psychologists recently examined the how odor influences emotion between male and female. Three groups of participants (half male, half female) were first subjected to different types of smell (pleasant, neutral, and unpleasant), and then filled out questionnaire of happiness. The data present the pattern of results obtained in the study, with higher scores indicating a higher level of happiness Odor pleasant neutral unpleasant Male n = 5 n = 5 n = 5 M = 8 M = 7 M = 0 SS = 6 SS = 5 SS = 4 Female n = 5 n = 5 n = 5 M = 7 M =2 M = 0 SS = 6 SS = 4 SS = 6 Note: grand mean =4 A) Conduct a hypotheses testing with α = .05 to evaluate the main effects and interactions (follow the four-step procedure). B) Calculate the effect size (partial η2) for the main effects and the interaction. C) Plot the cell means in a graph, with odor type on the x-axis. D) Based on the pattern of interaction shown in the graph,…arrow_forwardDr. Guidry conducts a study examining the relationship between the number of friends one has and the experience of daily stress and life satisfaction. She randomly samples 1,500 elderly men and women in Nashville, Tennessee (the state capital), located in the southern United States. Dr. Guidry submits her study for publication in a scientific journal. If one of the peer reviewers is concerned about the external validity of her study, which of the following is the most important aspect of Dr. Guidry's study to consider? the number of significant findings the random sampling technique used to recruit the participants the number of people in the sample the use of three measured variablesarrow_forward
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- Video Games. A pathological video game user (PVGU) is a video game user that averages 31 or more hours a week of gameplay. According to the article “Pathological Video Game Use among Youths: A Two-Year Longitudinal Study” (Pediatrics, Vol. 127, No. 2, pp. 319–329) by D. Gentile et al., in 2011, about 9% of children in grades 3–8 were PVGUs. Suppose that, today, seven youths in grades 3–8 are randomly selected. a. Assuming that the percentage of PVGUs in grades 3–8 is the same today as it was in 2011, determine the probability distribution for the number, X, who are PVGUs. b. Determine and interpret the mean of X. c. If, in fact, exactly three of the seven youths selected are PVGUs, would you be inclined to conclude that the percentage of PVGUs in grades 3–8 has increased from the 2011 percentage? Explain your reasoning. Hint: First consider the probability P(X ≥ 3). d. If, in fact, exactly two of the seven youths selected are PVGUs, would you be inclined to conclude that the percentage…arrow_forwardThe paper "From Dr. Kildare to Grey's Anatomy"† describes several studies of how the way in which doctors are portrayed on television might influence public perception of doctors. One study was described as follows. Rebecca Chory, Ph.D., now an associate professor of communication at West Virginia University, began studying the effect of such portrayals on patients' attitudes toward physicians. Using a survey of 300 undergraduate students, she compared perceptions of physicians in 1992—the end of the era when physicians were shown as all-knowing, wise father figures—with those in 1999, when shows such as ER and Chicago Hope (1994–2000) were continuing the transformation to showing the private side and lives of physicians, including vivid demonstrations of their weaknesses and insecurities. Dr. Chory found that, regardless of the respondents' personal experience with physicians, those who watched certain kinds of television had declining perceptions of physicians' composure and regard…arrow_forward3. A researcher was interested in the effects of a drug on depression. Subjects were randomly assigned to one of the three groups. Subjects in the control group received a placebo and the subjects in the two treatment groups received either a 0.2 mg or a 0.4 mg dosage of the drug. After several weeks of drug (or placebo) treatment, the researcher measured the subjects' level of depression (a low score indicating greater depression) The following data were obtained. Placebo 0.2 mg 0.4 mg 12 11 12 10 9. 14 11 11 17 13 13 16 15 7 16 12 Mean of X = 10 14 12 S^2 = 5.6 8.4 Using 5% of significance, test the hypothesis that the three groups differ in their effectiveness.arrow_forward
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