Under what circumstances is it advisable to switch to a between-subjects design instead of using a within-subjects design?
> The paper “Predictors of complementary therapy use Among Asthma Patients: results of a Primary care Survey” (Health and Social Care in the Community [2008]: 155–164) described a study in which each person in a large sample of asthma patients responded to
> A certain university has 10 vehicles available for use by faculty and staff. Six of these are vans and four are cars. On a particular day, only two requests for vehicles have been made. Suppose that the two vehicles to be assigned are chosen at random fr
> The report “State of the news Media 2015” (Pew research center, April 29, 2015) published the accompanying circulation numbers for 15 news magazines (such as Time and The New Yorker) for 2014: / Explain why the average may not be the best measure of a
> Two different airlines have a flight from Los Angeles to New York that departs each weekday morning at a certain time. Let E denote the event that the first airline’s flight is fully booked on a particular day, and let F denote the event that the second
> A large cable company reports that 80% of its customers subscribe to cable TV, 42% subscribe to Internet service, and 97% subscribe to at least one of cable TV and Internet service. In Exercise 5.26, you constructed a hypothetical 1000 table to calculate
> There are two traffic lights on Shelly’s route from home to work. Let E denote the event that Shelly must stop at the first light, and define the event F in a similar manner for the second light. Suppose that P (E) = 0.4, P (F ) = 0.3 and P (E ∩ F ) = 0.
> Consider the following events: C = event that a randomly selected driver is observed to be texting or using a hand-held cell phone A = event that a randomly selected driver is observed driving a car V = e vent that a randomly selected driver is observ
> Students at a particular university use an online registration system to select their courses for the next term. There are four different priority groups, with students in Group 1 registering first, followed by those in Group 2, and so on. Suppose that t
> A man who works in a big city owns two cars, one small and one large. Three-quarters of the time he drives the small car to work, and one-quarter of the time he takes the large car. If he takes the small car, he usually has little trouble parking and so
> A large cable TV company reports the following: 80% of its customers subscribe to its cable TV service 42% of its customers subscribe to its Internet service 32% of its customers subscribe to its telephone service 25% of its customers subscribe to bot
> The paper “good for women, good for Men, bad for People: Simpson’s Paradox and the importance of Sex-Specific Analysis in observational Studies” (Journal of Women’s Health and Gender
> Suppose that an individual is randomly selected from the population of all adult males living in the United States. Let A be the event that the selected individual is over 6 feet in height, and let B be the event that the selected individual is a profess
> The article “u.S. investors Split between digital and traditional banking” (www.gallup.com, August 5, 2016, retrieved April 25, 2017) summarized data from a Gallup survey of a random sample of 1019 U.S. adults with investments of $10,000 or more. Based o
> Data on weekday exercise time for 20 males, consistent with summary quantities given in the paper “an ecological Momentary assessment of the Physical activity and Sedentary behaviour Patterns of university Students” (H
> Lyme disease is transmitted by infected ticks. Several tests are available for people with symptoms of Lyme disease. One of these tests is the EIA/IFA test. The paper “lyme disease testing by large commercial laboratories in the united States” (Clinical
> The article “Americans growing More concerned About head injuries in Football” (www.theharrispoll.com, december 21, 2015, retrieved April 25, 2017) describes a survey of 2096 adult Americans. Survey participants were a
> An electronics store sells two different brands of DVD players. The store reports that 30% of customers purchasing a DVD choose Brand 1. Of those that choose Brand 1, 20% purchase an extended warranty. Consider the chance experiment of randomly selecting
> The accompanying table summarizes data from a Gallup Survey of 3594 parents with school-aged children (“Five insights into u.S. Parents’ Satisfaction with education,” August 25, 2016, www.gallup.com,
> The paper “Action bias among elite Soccer goalkeepers: the case of Penalty Kicks” ( Journal of Economic Psychology [2007]: 606–621) presents an interesting analysis of 286 penalty kicks in televised championship soccer games from around the world. In a p
> The accompanying data are from the article “characteristics of buyers of hybrid honda civic iMA: Preferences, decision Process, vehicle ownership, and willingness-to-Pay” (institute for environmental decisions, novembe
> Suppose that 20% of all teenage drivers in a certain county received a citation for a moving violation within the past year. Assume in addition that 80% of those receiving such a citation attended traffic school so that the citation would not appear on t
> The following statement is from a letter to the editor that appeared in USA TODAY (September 3, 2008): “Among Notre Dame’s current undergraduates, our ethnic minority students (21%) and international students (3%) alone equal the percentage of students w
> Airline tickets can be purchased online, by telephone, or by using a travel agent. Passengers who have a ticket sometimes don’t show up for their flights. Suppose a person who purchased a ticket is selected at random. Consider the following events: O =
> The report “improving undergraduate learning” (Social Science research council, 2011) summarizes data from a survey of several thousand college students. These students were thought to be representative of the population of all college students in the Un
> For each brand of car sold in the United States, data on a customer satisfaction rating (called the APEAL rating) are given (USA TODAY, March 29, 2016). The APEAL rating is a score between 0 and 1,000, with higher values indicating greater satisfaction.
> The report “teens, Social Media & technology overview 2015” (Pew research center, April 9, 2015) summarized data from a large survey of teens age 13–17. Of those surveyed, 71% use Facebook and 52% use Instagram. Use these percentages to explain why the t
> The table at the top of the next page describes the approximate distribution of students by sex and college at a midsize public university in the West. Suppose you were to randomly select one student from this university. a. What is the probability that
> A rental car company offers two options when a car is rented. A renter can choose to pre-purchase gas or not and can also choose to rent a GPS device or not. Suppose that the events A = event that gas is pre-purchased B = event that a GPS is rented are
> In some states, such as Iowa and Nevada, the presidential primaries are decided by caucuses rather than a primary election. The caucuses determine winners at the precinct level, and turnout is often low. As a result, it is not uncommon in a close race to
> a. Suppose events E and F are mutually exclusive with P(E )= 0.14 and P(F ) = 0.76. i. What is the value of P(E ∩ F )? ii. What is the value of P(E ∪ F )? b. Suppose that for events A and B, P(A) = 0.24, P(B) = 0.24, and P(A ∪ B) = 0.48. Are A and B
> An appliance manufacturer offers extended warranties on its washers and dryers. Based on past sales, the manufacturer reports that of customers buying both a washer and a dryer, 52% purchase the extended warranty for the washer, 47% purchase the extended
> The paper “Predictors of complementary therapy use Among Asthma Patients: results of a Primary care Survey” (Health and Social Care in the Community [2008]: 155–164)۔ described a study in which each person in a large sample of asthma patients responded t
> The accompanying data are from the article “characteristics of buyers of hybrid honda civic iMA: Preferences, decision Process, vehicle ownership, and willingness-to-Pay” (institute for environmental decisions, novembe
> False positive results are not uncommon with mammograms, a test used to screen for breast cancer. For a woman who has a positive mammogram, the probability that she actually has breast cancer is less than 0.05 if she is under 40 years old, and ranges fro
> Consider a chance experiment that consists of selecting a student at random from a high school with 3000 students. a. In the context of this chance experiment, give an example of two events that would be mutually exclusive. b. In the context of this ch
> The accompanying data are a subset of data that appeared in the paper “ladies First? a Field Study of Discrimination in coffee Shops” (Applied Economics [april 2008]). The data are the times (in seconds) between orderi
> A large retail store sells headphones. A customer who purchases headphones can pay either by cash or credit card. An extended warranty is also available for purchase. Suppose that the events M = event that the customer pays by cash E = e vent that the
> Each time a class meets, the professor selects one student at random to explain the solution to a homework problem. There are 40 students in the class, and no one ever misses class. Luke is one of these students. What is the probability that Luke is sele
> a. Suppose events E and F are mutually exclusive with P(E ) 5 0.41 and P(E ) 5 0.23. i. What is the value of P(E ∩ F )? ii. What is the value of P(E ∪ F )? b. Suppose that for events A and B, P(A) 5 0.26, P(B) 5 0.34, and P(A ∪ B) 5 0.47. Are A and B
> A large cable company reports that 80% of its customers subscribe to its cable TV service, 42% subscribe to its Internet service, and 97% subscribe to at least one of these two services. a. Use the given probability information to set up a hypothetical
> There are two traffic lights on Shelly’s route from home to work. Let E denote the event that Shelly must stop at the first light, and define the event F in a similar manner for the second light. Suppose that P(E ) = 0.4, P(F ) = 0.3, and P(E ∩ F ) = 0.1
> A bank offers both adjustable-rate and fixed-rate mortgage loans on residential properties, which are classified into three categories: single-family houses, condominiums, and multifamily dwellings. Suppose each loan made in 2016 was classified according
> A Gallup survey found that 64% of women and 55% of men said that they favor affirmative action programs for women (gallup Poll Social Series, July 28, 2016). Suppose that this information is representative of U.S. adults. If a U.S. adult is selected at r
> A small college has 2700 students enrolled. Consider the chance experiment of selecting a student at random. For each of the following pairs of events, indicate whether or not you think they are mutually exclusive and explain your reasoning. a. the even
> Six people hope to be selected as a contestant on a TV game show. Two of these people are younger than 25 years old. Two of these six will be chosen at random to be on the show. a. What is the sample space for the chance experiment of selecting two of t
> A deck of 52 cards is mixed well, and 5 cards are dealt. a. It can be shown that (disregarding the order in which the cards are dealt) there are 2,598,960 possible hands, of which only 1287 are hands consisting entirely of spades. What is the probabilit
> The accompanying data on number of cell phone minutes used in one month are consistent with summary statistics published in a report of a marketing study of San Diego residents (tele-truth, March 2009): Explain why the average may not be the best measure
> The report “Trends in College Pricing 2015” (trends.college board.org/sites/default/files/2015-trends-college-pricing -final-508.pdf, retrieved April 17, 2017) included the information in the accompanying relative freq
> The following list contains several variables that differentiate college students. physical attractiveness intelligence alcohol consumption shyness exam anxiety hours of sleep per night hours of television per week a. Select two variables from the list t
> A researcher has a sample of 30 rats that are all cloned from the same source. The 30 rats are genetically identical and have been raised in exactly the same environment since birth.
> Explain how the purpose of a correlational study differs from the purpose of an experimental study.
> What characteristic differentiates a pretest–posttest design from a time-series design?
> A researcher has demonstrated that a new noncompetitive physical education program significantly improves self-esteem for children in a kindergarten program. a. What additional information can be obtained by introducing participant motor skill ability as
> A two-factor analysis of variance is used to evaluate the significance of the mean differences for the two-factor research study shown in the following table. The study is evaluating the effects of sugary versus nonsugary snacks on the activity level of
> In addition to the key words, you should also be able to define each of the following terms: Scatter plot Linear relationship Pearson correlation Monotonic relationship Spearman correlation Statistical significance of a correlation Regression Third-varia
> A researcher would like to use a factorial study to compare two programs designed to help people stop smoking. The smoking behavior of each participant will be measured at the beginning of the program, at the end of the program, and again four months aft
> Explain what is meant by the concept that main effects and interactions are independent.
> Describe the similarities and differences between a research proposal and a research report.
> Suppose a researcher conducts a two-factor study comparing two treatments (I and II) for college graduates versus adults with no college experience. The structure of the study is shown in the following matrix. a. If the results show that college graduate
> In a classic study, Shrauger (1972) examined the effect of an audience on performance for two groups of participants: high self-esteem and low self-esteem individuals. The participants in the study were given a problem-solving task with half of the indiv
> In addition to the key words, you should also be able to define the following terms: Two-factor design Single-factor design Levels Three-factor design Higher-order factorial design
> Explain how holding a participant variable such as gender constant prevents the variable from becoming a confounding variable and can help reduce the variance within treatments. Identify the problem with using this method.
> A researcher wants to describe the effectiveness of a new program (compared to the old program) for teaching reading to elementary school children. Describe how this study could be done as a posttest-only nonequivalent control group design. Next, describ
> Explain why partial counterbalancing is sometimes necessary.
> Describe the circumstances in which counterbalancing is used and explain what it is trying to accomplish.
> Time-related factors and order effects can threaten internal validity for some within-subjects experiments. Describe the kind of study for which these factors can be a problem and explain how they can be a confounding variable in some within-subjects des
> Describe the characteristics of a within-subjects experimental research design.
> Describe the disadvantages of a multiple-treatment design, compared to a two-treatment design, for a within-subjects experiment.
> Identify the circumstances in which it is useful to write a research proposal before conducting the actual research study. In each case, explain why the proposal would be useful.
> Describe the basic characteristics of a pre–post design and explain why these designs are not true experiments.
> In addition to the key words, you should also be able to define the following terms: Individual differences Differential effects History Instrumentation Order effects Maturation Statistical regression Interrupted time-series designs Single-case, or sing
> Describe how individual differences can produce large variance within treatments and explain why this is a problem in a between subjects experiment.
> A sociologist would like to describe the characteristics of people who live and work in small towns (population less than 2,000). (a) Explain how this question might be answered using qualitative research. (b) Explain how the question might be answered u
> Selection bias and individual differences are both potential problems dealing with the participants in a study. a. Identify which of these is a threat to internal validity and which is a threat to external validity, and describe how each one is a threat.
> Identify the advantages of a multiple-group design compared to an experiment with only two groups.
> Describe some of the problems that can arise when the participants in one treatment condition of a between-subjects experiment are allowed to communicate with participants in a different condition.
> In addition to the key words, you should also be able to define the following terms: Within-subjects design Repeated-measures design Practice Fatigue Contrast effect Complete counterbalancing Partial counterbalancing Latin square Participant attrition
> A recent survey at a major corporation found that employees who regularly participated in the company fitness program tended to have fewer sick days than the employees who did not participate. However, because the study was not a true experiment, you can
> Define extraneous variable and explain how extraneous variables can become confounding variables.
> For each of the following, identify the section of a research report that would probably contain the desired information: How many individuals participated in the study, and what are their characteristics? Why was the study done? Did the study use any
> Briefly explain how a participant characteristic, such as personality, could be a confounding variable in a between-subjects experiment.
> In a between-subjects design, each individual score is obtained from a separate participant. a. Briefly explain why this is an advantage. b. Briefly explain why this is a disadvantage.
> At the beginning of this chapter (p. 186), we described a study comparing the effectiveness of studying material printed on paper to studying material displayed on a computer screen (Ackerman & Goldsmith, 2011). Explain why this study is an example of a
> Describe the advantages of a two-group design compared to an experiment with more than two groups.
> In addition to the key words, you should also be able to define the following terms: Within-subjects design Between-subjects design Independent-measures design Random assignment Variance within treatments, or variance within groups Differential attrit
> Explain how the process of randomly assigning participants to treatment conditions should prevent a participant variable such as age or gender from becoming a confounding variable.
> What is the novelty effect, and how does it affect a study’s external validity?
> Identify the two characteristics needed for a research study to qualify as an experiment.
> Explain how a researcher using simple random sampling can still obtain a biased sample.
> It has been demonstrated that students with high self-esteem tend to have higher grades than students with low self-esteem. Does this relationship mean that higher self-esteem causes better academic performance? Does it mean that better academic performa
> Explain the distinction between naturalistic observation and participant observation, and describe the situations in which participant observation may be particularly useful.
> By manipulating the participants’ experiences, it is possible to examine how people’s performance and attitudes are influenced by success and failure. To do this, researchers can give some participants a feeling of success and others a feeling of failure
> For each of the following scenarios, identify which research strategy is used: descriptive, correlational, experimental, or nonexperimental. (Note: For now, do not differentiate between nonexperimental and quasi-experimental studies. The distinction betw
> Describe how participant reactivity can be a threat to external validity; that is, how can participant reactivity limit the ability to generalize research results?
> Describe how experimenter bias can be a threat to internal validity; that is, how can experimenter bias provide an explanation for the scores in one condition being higher than the scores in a second condition?
> Can a research study be an experiment without a control group? Can a study be an experiment without controlling extraneous variables?
> In addition to the key words, you should also be able to define the following terms: Third-variable problem Directionality problem Confounding variable Random process Placebo Mundane realism Experimental realism
> Describe the advantages and disadvantages of convenience sampling.
> Explain how inter-rater reliability is established.
> Suppose that a social scientist has developed a questionnaire intended to measure the quality of romantic relationships. Describe how you could evaluate the reliability of the questionnaire.
