?A professor in the psychology department would like to determine whether there has been

Parametric tests (such as t or ANOVA) differ from nonparametric tests (such as chi-square) primarily in terms of the assumptions they require and the data they use. Explain these differences.

The student population at the state college consists of \(30 \%\) freshmen, \(25 \%\) sophomores, \(25 \%\) juniors, and \(20 \%\) seniors. The college theater department recently staged a production of a modern musical. A researcher recorded the class status of each student entering the theater and found a total of 20 freshmen, 23 sophomores, 22 juniors, and 15 seniors. Is the distribution of class status for theatergoers significantly different from the distribution for the general college? Test at the .05 level of significance. Equation Transcription: Text Transcription: 30% 25% 25% 20%

A developmental psychologist would like to determine whether infants display any color preferences. A stimulus consisting of four color patches (red, green, blue, and yellow) is projected onto the ceiling above a crib. Infants are placed in the crib, one at a time, and the psychologist records how much time each infant spends looking at each of the four colors. The color that receives the most attention during a 100-second test period is identified as the preferred color for that infant. The preferred colors for a sample of 80 infants are shown in the following table: a. Do the data indicate any significant preferences among the four colors? Test at the .05 level of significance. b. Write a sentence demonstrating how the outcome of the hypothesis test would appear in a research report.

Data from the Department of Motor Vehicles indicate that 80% of all licensed drivers are older than age 25. a. In a sample of n = 50 people who recently received speeding tickets, 33 were older than age 25 and the other 17 were age 25 or younger. Is the age distribution for this sample significantly different from the distribution for the population of licensed drivers? Use \(\alpha\) = .05. b. In a sample of n = 50 people who recently received parking tickets, 36 were older than age 25 and the other 14 were age 25 or younger. Is the age distribution for this sample significantly different from the distribution for the population of licensed drivers? Use \(\alpha\) = .05.

A psychologist examining art appreciation selected an abstract painting that had no obvious top or bottom. Hangers were placed on the painting so that it could be hung with any one of the four sides at the top. The painting was shown to a sample of n = 60 participants, and each was asked to hang the painting in the orientation that looked correct. The following data indicate how many people chose each of the four sides to be placed at the top. Are any of the orientations selected more (or less) often than would be expected simply by chance? Test with \(\alpha\) = .05.

A professor in the psychology department would like to determine whether there has been a significant change in grading practices over the years. It is known that the overall grade distribution for the department in 1985 had 14% As, 26% Bs, 31% Cs, 19% Ds, and 10% Fs. A sample of n = 200 psychology students from last semester produced the following grade distribution: Do the data indicate a significant change in the grade distribution? Test at the .05 level of significance.

Automobile insurance is much more expensive for teenage drivers than for older drivers. To justify this cost difference, insurance companies claim that the younger drivers are much more likely to be involved in costly accidents. To test this claim, a researcher obtains information about registered drivers from the department of motor vehicles and selects a sample of n = 300 accident reports from the police department. The motor vehicle department reports the percentage of registered drivers in each age category as follows: 16% are younger than age 20; 28% are 20 to 29 years old; and 56% are age 30 or older. The number of accident reports for each age group is as follows: a. Do the data indicate that the distribution of accidents for the three age groups is significantly different from the distribution of drivers? Test with \(\alpha\) = .05. b. Compute Cohen’s w to measure the size of the effect. c. Write a sentence demonstrating how the outcome of the hypothesis test and the measure of effect size would appear in a research report.

A communications company has developed three new designs for a smartphone. To evaluate consumer response, a sample of 240 college students is selected and each student is given all three phones to use for one week. At the end of the week, the students must identify which of the three designs they prefer. The distribution of preference is as follows: a. Do the results indicate any significant preferences among the three designs? b. Compute Cohen’s w to measure the size of the effect.

In Problem 8, a researcher asked college students to evaluate three new smartphone designs. However, the researcher suspects that college students may have criteria that are different from those used by older adults. To test this hypothesis, the researcher repeats the study using a sample of n = 60 older adults in addition to a sample of n = 60 students. The distribution of preference is as follows: Do the data indicate that the distribution of preferences for older adults is significantly different from the distribution for college students? Test with \(\alpha\) = .05.

Earlier in the chapter, we introduced the chi-square test of independence with a study examining the relationship between personality and color preference. The following table shows the frequency distribution for a group of n = 200 students who were classified in terms of personality (introvert, extrovert) and in terms of color preference (red, yellow, green, or blue). Do the data indicate a significant relationship between the two variables? Test with \(\alpha\) = .05.

Liu et al. (2015) recently reported the results of a study examining whether happy people live longer. The study followed a large sample of British women, aged 50 to 69 over a 10-year period. At the beginning of the study the women were asked several questions, including how often they felt happy. After 10 years, roughly 4% of the women had died. The following table shows a frequency distribution similar to the results obtained in the study. a. Do the data indicate a significant relationship between living longer and being happy most of the time? Test with \(\alpha\) = .05. b. Compute the phi-coefficient to measure the size of the treatment effect.

Many businesses use some type of customer loyalty program to encourage repeat customers. A common example is the buy-ten-get-one-free punch card. Drèze and Nunes (2006) examined a simple variation of this program that appears to give customers a head start on completing their cards. One group of customers at a car wash was given a buy-eight-get-one-free card and a second group was given a buy-ten-get-one-free card that had already been punched twice. Although both groups needed eight punches to earn a free wash, the group with the two free punches appeared to be closer to reaching their goal. A few months later, the researchers recorded the number of customers who had completed their cards and earned their free car wash. The following data are similar to the results obtained in the study. Do the data indicate a significant difference between the two card programs? Test with \(\alpha=.05\). Equation Transcription: Text Transcription: alpha=.05

In a classic study, Loftus and Palmer (1974) investigated the relationship between memory for eyewitnesses and the questions they are asked. In the study, participants watched a film of an automobile accident and then were questioned about the accident. One group was asked how fast the cars were going when they “smashed into” each other. A second group was asked about the speed when the cars “hit” each other, and a third group was not asked any question about the speed of the cars. A week later, the participants returned to answer additional questions about the accident, including whether they recalled seeing any broken glass. Although there was no broken glass in the film, several students claimed to remember seeing it. The following table shows the frequency distribution of responses for each group. a. Does the proportion of participants who claim to remember broken glass differ significantly from group to group? Test with \(\alpha\) = .05. b. Compute Cramér’s V to measure the size of the treatment effect. c. Describe how the phrasing of the question influenced the participants’ memories. d. Write a sentence demonstrating how the outcome of the hypothesis test and the measure of effect size would be reported in a journal article.

The Internet is rapidly becoming an essential source of information about health, nutrition, finances, and current events. Neunschwander, Abbott, and Mobley (2012) were interested in inequality of access to the Internet as a function of the characteristics of the participant. They recruited a very large sample of participants from the Indiana Supplemental Nutrition Assistance Program and surveyed them about their access to the technology. They observed that racial minorities, older persons, and persons with lower educational attainment were less likely to have a functioning computer at home and, relatedly, were less likely to have access to the Internet. Below are frequencies similar to those observed by the researchers. a. Does the proportion of participants who own a computer differ significantly from group to group? Test with \(\alpha\) = .05. b. Compute Cramér’s V to measure the size of the treatment effect. c. Write a sentence demonstrating how the outcome of the hypothesis test and the measure of effect size would be reported in a journal article.

Captive animals in laboratories or zoos benefit from environmental enrichment. In a recent experiment on the effects of enrichment on animal behavior, Robbins and Margulis (2014) compared the effects of different types of auditory enrichment on captive gorillas. In their experiment, three gorillas—Koga, Lily, and Sidney—were exposed to either natural sounds, classical music, or rock music. The researchers counted the number of times the gorillas oriented toward the sound source. Frequencies like those observed by the researchers are listed below. a. Do the results indicate any significant preferences among the three types of music? b. Write a sentence demonstrating how the outcome of the hypothesis test would be reported in a journal article.

Many parents allow their underage children to drink alcohol in limited situations when an adult is present to supervise. The idea is that teens will learn responsible drinking habits if they first experience alcohol in a controlled environment. Other parents take a strict no drinking approach with the idea that they are sending a clear message about what is right and what is wrong. Recent research, however, suggests that the more permissive approach may actually result in more negative consequences (McMorris et al., 2011). The researchers surveyed a sample of 200 students each year from ages 14 to 17. The students were asked about their alcohol use and about alcohol-related problems such as binge drinking, fights, and blackouts. The following table shows data similar to the results from the study. a. Do the data show a significant relationship between the parents’ rules about alcohol and subsequent alcohol-related problems? Test with \(\alpha\) = .05. b. Compute Cramér’s V to measure the strength of the relationship.

A recent study indicates that people tend to select video game avatars with characteristics similar to those of their creators (Bélisle & Bodur, 2010). Participants who had created avatars for a virtual community game completed a questionnaire about their personalities. An independent group of viewers examined the avatars and recorded their impressions of the avatars. One personality characteristic considered was introverted/extroverted. The following table shows the frequency distribution of personalities for participants and the avatars they created. a. Is there a significant relationship between the personalities of the participants and the personalities of their avatars? Test with \(\alpha\) = .05. b. Compute the phi-coefficient to measure the size of the effect.

Suppose that a researcher is interested in differences between young adults and older adults with respect to social media preferences. The researcher asked participants to indicate their preference for a specific social media application by checking all that apply among the following: Twitter, Facebook, and Snapchat™. The researcher observes the following: Identify the assumptions of the chi-square test that would be violated if the researcher performed a chi square test on the frequencies above.

Research indicates that people who volunteer to participate in research studies tend to have higher intelligence than non-volunteers. To test this phenomenon, a researcher obtains a sample of 200 high school students. The students are given a description of a psychological research study and asked whether they would volunteer to participate. The researcher also obtains an IQ score for each student and classifies the students into high, medium, and low IQ groups. Do the preceding data indicate a significant relationship between IQ and volunteering? Test at the .05 level of significance.