Unit 6 (notes)

Question 1

What is the main difference between a correlational design and an experimental design?
a. Correlational designs only involve the use of two independent variables, whereas experimental designs can utilize two or more.
b. Correlation designs but not experimental designs infer causation.
c. Experimental designs but not correlational designs infer causation.
d. Experimental designs have both independent and dependent variables, whereas
correlational designs only have independent variables.

Answer 1

c

Question 2

Which type of hypothesis states that the independent variable will have no effect on the dependent variable?
a. alternative hypothesis
b. null hypothesis
c. directional research hypothesis
d. nondirectional research hypothesis

Answer 2

b

Question 3

The statement, “Female PSYC 2250 students study longer hours than male PSYC 2250 students” represents:
a. a null hypothesis.
b. an alternative hypothesis.
c. a nondirectional research hypothesis.
d. a H0 hypothesis.

Answer 3

b

Question 4

Derek is investigating shopping behaviour. He recruits people at a mall, gathers some demographic data, and divides them up into three categories: those who get $100 in mall gift certificates, those who get $50 in mall gift certificates, and those who get no gift certificates. He records the amount of goods sold to each person at the end of his or her shopping day. Amazingly, those who receive the $100 in gift certificates averaged close to $500 spent, those who got $50 in gift certificates averaged $230 in spending, and those who did not receive a gift certificate spent an average of only $95. Which of the following statements is true?
a. The gift certificates represent the independent variable and the amount spent the dependent variable.
b. The gift certificates represent the dependent variable and the amount spent the independent variable.
c. Both the gift certificates and the amount spent represent dependent variables.
d. Both the gift certificates and the amount spent represent independent variables.

Answer 4

a

Question 5

Which of the following is an absolute necessity when making a causal inference based on the information gained via an experimental design?
a. Both an independent and dependent variable must be present in the study.
b. Operational definitions of all variables need to be clear.
c. Covariation between the independent and dependent variables must occur.
d. The alternative and research hypothesis need to be mutually exclusive.

Answer 5

c

Question 6

Mu (μ) stands for a(n):
a. sample mean.
b. random sample.
c. population mean.
d. independent variable.

Answer 6

c

Question 7

Which of the following groups gets exposed to the independent variable?
a. control group
b. extraneous group
c. experimental group
d. Both b and c are correct.

Answer 7

c

Question 8

Control groups provide all of the following except:
a. control groups provide a baseline for comparison.
b. control groups help to eliminate factors like confounding or extraneous variables in the
environment that may be plausible explanations.
c. control groups maximize differences between experimental conditions.
d. control groups help to minimize error due to individual differences.

Answer 8

c

Question 9

An investigator wants to study the smoking attitudes of students at a certain middle school. She gives her survey to every student enrolled at the middle school. She has just studied:
a. the population.
b. the random sample.
c. a biased sample.
d. a stratified sample.

Answer 9

a

Question 10

All experimental designs in psychology will include:
a. attempts to control extraneous variables and error.
b. a minimum of two independent variables.
c. a minimum of two dependent variables.
d. attempts to distinguish between internal and external validity.

Answer 10

a

Question 11

___________ procedures are used to avoid experimenter and participant bias.
a. T-test
b. ANOVA
c. Single-blind d. Double-blind

Answer 11

d

Question 12

Liz is looking over her final marks, based on 100, for her research methods course. She notices that one student’s final mark was 120 and another student’s final mark was -13. What are these bizarre marks called?
a. mu marks
b. outliers
c. μ2
d. type 1 errors
e. type 2 errors

Answer 12

b

Question 13

Statistical significance indicates:
a. that a real inference about the data can be made regarding the probability of a chance occurrence of a response.
b. that the difference between the mean score on the dependent variable for the experimental group is larger than would be expected by chance than the mean score on the dependent variable for the control group if the null hypothesis was true.
c. that the difference between the mean score on the independent variable for the control group is larger than would be expected by chance than the mean score on the dependent variable for the experimental group if the null alternative hypothesis was true.
d. that alpha = 0.005.

Answer 13

b

Question 14

Based on his data, Bob rejects the null hypothesis. However, in reality, the null hypothesis was true. Bob has just made a(n):
a. type I error.
b. type II error.
c. type III error.
d. outlier error.

Answer 14

a

Question 15

In 1998 Tammy ran a study, and the data indicated that the null hypothesis was true. Sara ran the exact same study yesterday and rejects the null hypothesis. Which of the following is true?
a. Sara has made a type I error.
b. Tammy made a type II error.
c. Alpha should have been set to 0.95.
d. Both a and b are possible truths.
e. Both a and c are possible truths.

Answer 15

d

Question 16

Alpha is theoretically identical to a:
a. type I error.
b. type II error.
c. the null hypothesis.
d. power of a study.

Answer 16

a

Question 17

ANOVA (analysis of variance) and t-tests are examples of:
a. descriptive statistics.
b. inferential statistics.
c. true null hypotheses.
d. true alternative hypothesis.

Answer 17

b

Question 18

In statistics, the Greek letter alpha () is called the level of significance. Most studies in psychology set the alpha level in an experiment to:
a. 0.05.
b. 0.005.
c. 0.5.
d. 0.01.

Answer 18

a

Question 19

When compared to between-subjects designs, within-subject designs:
a. require a greater number of participants.
b. must have an independent matched control group.
c. must attempt to address the problem of carry-over effects. d. must be aware of the problem of individual differences.

Answer 19

c

Question 20

In which experimental design are participants placed in both the experimental and control group?
a. random groups design
b. matched groups design
c. natural groups design
d. repeated-measures design

Answer 20

d

Question 21

A researcher is studying problem solving ability while listening to five different types of background noise: rap music, classical music, country music, rock music, and static white noise. The researcher presents all the different background noises to all the participants always in the same order (see above). The results indicate that problem solving is best in the rap condition and poorest in the static noise condition. What type of design is described above and which of the following is a probable explanation of the findings?
a. between-subjects design; carry-over effects
b. between-subjects design; participant fatigue
c. within-subjects design; practice effects
d. within-subjects design; participant fatigue

Answer 21

d

Question 22

Type I and Type II errors result because:
a. researchers rarely conduct internally valid studies.
b. researchers rarely conduct externally valid studies.
c. the null hypothesis is always meant to be true.
d. decision making using inferential statistics is based on probabilities.

Answer 22

d

Question 23

Double-blind experiments are typically used to control:
a. individual difference variables.
b. the possibility of subject loss.
c. the influence of extraneous variables.
d. demand characteristics and experimenter effects.

Answer 23

d

Question 24

A researcher performs a t-test on the mean scores for an experimental and control group. The probability of the statistical value obtained is 0.001. The researcher should:
a. accept the null hypothesis.
b. reject the null hypothesis.
c. neither accept nor reject the null hypothesis.
d. reduce the alpha level to 0.001.

Answer 24

b

Question 25

What is the general rule for counterbalancing a repeated-measures design?
a. Each condition must appear only once in the first ordinal position.
b. Each experimental condition must appear only in the first, second, or third ordinal position.
c. Each condition must appear in each ordinal position exactly once.
d. Each condition of the experiment must appear in each ordinal position equally often.

Answer 25

d

Question 26

Jessica is studying the effects of alcohol on skating speed. Participants are randomly assigned to a group that either gets a) a real beer, b) a “fake” non-alcoholic beer, or c) nothing to drink. The average time to skate around the course in the “real beer” group is 36 seconds. Which of the following average scores for the other two groups would allow Jessica to conclude that the apparent effect of alcohol was nothing but a placebo effect?
a. the “fake” beer group = 36 seconds; the nothing to drink group = 23 seconds.
b. the “fake” beer group = 30 seconds; the nothing to drink group = 23 seconds.
c. the “fake” beer group = 23 seconds; the nothing to drink group = 23 seconds.
d. the “fake” beer group = 36 seconds; the nothing to drink group = 36 seconds.

Answer 26

a