Test Bank for Essentials of Statistics for the Behavioral

Page 1 Test Bank for Essentials of Statistics for the Behavioral Sciences 3e by Susan Nolan, Thomas Heinzen (All Chapters Answers at the end of each chapter) Chapter 01- Critical-Thinking

• Schacter and Gross (1968) gathered data from a group of 60 male students for about one

hour in the afternoon. At the end of this period of time, a clock on the wall was correct (5:30 P.M.) for 20 participants, slow (5:00 P.M.) for 20 others, and fast (6:00 P.M.) for 20 more. The actual time for all groups was 5:30 P.M., the usual dinnertime for these students. While participants filled out a final questionnaire, the experimenters provided crackers for the students to eat. The weight of the crackers each student consumed was measured. The arithmetic means were 5:00 P.M. group, 20 grams; 5:30 P.M. group, 30 grams; 6:00 P.M. group, 40 grams. Identify for this study the (a) population, (b) sample, (c) independent variable, (d) levels of the independent variable, (e) dependent variable, (f) descriptive statistics, and (g) any inferences warranted by this study.

• Hsee and Tang (2007) reported the results of a study in which 195 college students

completed a happiness scale (from 1 to 7) just prior to taking their midterm exam. On this scale, 1 corresponded to very unhappy and 7 to very happy. On average, the students rated their happiness as 6.18. Identify for this study the (a) population, (b) sample, (c) dependent variable, and (d) descriptive statistic.

• A New York Times article published on April 24, 2007, reported the research of Dr.

Giorgio Vallortigara, a neuroscientist at the University of Trieste, Italy. In the study, Dr.Vallortigara assessed whether a dog's tail wags in a preferred direction in response to positive as opposed to negative stimuli. Dr. Vallortigara recruited 30 dogs that were family pets. While filming a dog's tail from above, he allowed the dog to view (through a slot in its cage) its owner, an unfamiliar human, a cat, and an unfamiliar dominant dog.The study found that dogs' tails wagged to the right for the owner and to the left for the unfamiliar dominant dog. Identify for this study the (a) population, (b) sample, (c) independent variable, (d) levels of the independent variable, and (e) dependent variable.

• An elementary school teacher is researching the relation between sugar consumption

and activity level in preschool children. The teacher gives 30 preschool children 0 milligrams, 20 milligrams, or 50 milligrams of sucrose (sugar) in a breakfast drink. He then observes their behavior for 30 minutes during their morning outdoor play period, coding their activity level. Identify for this study the (a) population, (b) sample, (c) independent variable, (d) levels of the independent variable, and (e) dependent variable.

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Page 2

• In an experiment designed to assess the effects of disclosure of ingredients on the

experience of taste, Lee, Frederick, and Ariely (2006) approached patrons at a local pub and asked them to taste and rate a new beer: the MIT Brew. Some participants were told about the secret ingredient in the beer (a few drops of balsamic vinegar) either before tasting (before condition) or after tasting but before rating (after condition). Other participants were not told anything regarding the secret ingredient (not told condition).Identify for this study the (a) population, (b) sample, (c) independent variable, (d) levels of the independent variable, and (e) dependent variable.

• Identify at least one confounding variable that undermines the conclusion drawn in the

following fictional study: Professor Martin was interested in which of two popular statistics textbooks (Statistics: It Will Change Your Life and Statistics: Bigger, Better, Stronger) was better for students. Professor Martin compared the two texts by assigning one text to a section of statistics taught by Professor Miller from 10–11 A.M.on Monday, Wednesday, and Friday, and the other text to a section of statistics taught by Professor Mervin from 7–10 P.M. on Wednesday evenings. At the end of the term, all students took the same comprehensive test. Students to whom Statistics: Bigger, Better, Stronger was assigned performed better on the test than did students to whom Statistics: It Will Change Your Life was assigned. Professor Martin therefore concluded that the former textbook was the better one.

• An operational definition specifies the operations or procedures used to measure or

manipulate variables. A researcher is interested in investigating the relationship between thinking ability and educational success. What are some operational definitions that could be used in this study?

• What are some advantages in using a correlational design over an experimental design?

• What is the difference between a within-groups and a between-groups design? Why

would you use one design over another?

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Page 3

• You have been asked to design a study to determine the effects of smoking crack

cocaine on violent behavior. In order to avoid confounds related to prior drug use, the expectation is that this will be a between-groups design with 60 subjects who have no history of drug use. While living in the lab, one group of subjects will be asked to smoke crack once each day, a second group will be asked to smoke crack twice each day, and a third group will be asked to smoke a harmless compound once each day that appears to be crack. Over the course of the study, continuous behavioral observations will be made of all subjects to measure changes in the rates of violent behavior. Explain why you would not be able to conduct this study as expected and suggest an alternative research study design capable of determining the extent to which crack cocaine use and violent behavior are related.

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Page 4 Answer Key

• (a) The population is male students; (b) the sample is the 60 male students who

participated in the study; (c) the independent variable is the time that appeared on the clock; (d) the levels of the independent variable were correct, slow, or fast; (e) the dependent variable was the amount of crackers eaten by each student in grams; (f) there are three descriptive statistics provided: the means of each group, 20 grams for the slow group, 30 grams for the correct group, and 40 grams for the fast group; (g) one could infer that male students in general eat more when they believe it to be past their dinner hour.

• (a) The population is all college students just about to take a midterm exam; (b) the

sample is the 195 college students selected for this study; (c) the dependent variable is the student's rating on the happiness scale; and (d) the descriptive statistic is the average of the happiness ratings, which is 6.18.

• (a) The population is all dogs that are family pets; (b) the sample is 30 dogs selected for

this study; (c) the independent variable is the type of visual stimulus the dog was allowed to see; (d) the levels of the independent variable are owner, unfamiliar human, a cat, and an unfamiliar dominant dog; (e) the dependent variable is the direction in which the dog wagged its tail.

• (a) The population is all preschool children; (b) the sample is the 30 preschool children

who the teacher studied; (c) the independent variable is the amount of sucrose given to the children; (d) the levels of the independent variable are 0 milligrams, 20 milligrams, and 50 milligrams; (e) the dependent variable is each child's activity level.

• (a) The population is people who are patrons of pubs; (b) the sample is patrons

approached in this study; (c) the independent variable is whether the patron was told about the secret ingredient in the MIT Brew; (d) the levels of the independent variable are told before, told after, or not told; (e) the dependent variable is the patron's taste rating for the beer.

• There are several possible confounding variables that students may identify. One

confound is the time at which the sections of the class are taught: one in the evening and the other in the morning. A second confound is the distribution of the class sections: one meets once a week, the other three times a week. A third confound is that different instructors taught each of the courses. A fourth confound is the combination of the time of day and the duration of the classroom session: 3 mornings for one hour, evenings for three hours.

• Operational definitions are needed for the terms thinking ability and educational

success. This is because the variables do not have specific definitions. An example of an operational definition that could be used in this study is a question: What is the relationship between IQ scores on an intelligence scale (operational definition for thinking ability) and GPA (operational definition for educational success)? Another

example: It is hypothesized that problem-solving scores on a standardized test

(operational definition for thinking ability) will impact grades in an engineering course (operational definition for educational success).

• There are situations in which random assignment to groups may not be available, which

makes the use of a correlational design more practical because it has fewer restrictions.In correlational research, we do not have to manipulate any variables but only measure

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