Chapter 2 Questions

Which of the following is an operational definition of intelligence? a. The ability to comprehend relationships b. A score on an IQ test c. The ability to survive in the real world d. The product of the cerebral cortex of the brain

A score on an IQ test is an operational definition of intelligence, because it provides a measurement—perhaps not a completely accurate measure, but that is a separate issue. None of the other answer choices tells us how to measure or produce intelligence.

How does a meta-analysis relate to replicability?

If some studies replicate an effect and others do not, a researcher may conduct a meta-analysis that combines all studies as if they were one large study.

Should we be more impressed with results when the 95 percent confidence intervals are large or small? Should we be more impressed if the p value is large or small?

In both cases, smaller. A small 95 percent confidence interval indicates high confidence in the results. A small p value indicates a low probability of getting such a large difference merely by chance.

The more crowded a neighborhood, the lower the income.

Negative correlation between crowdedness and income.

Which of the following would an experimenter try to minimize or avoid? Falsifiability, independent variables, dependent variables, blind observers, or demand characteristics.

Of these, only demand characteristics are to be avoided. If you did not remember that falsifiability is a good feature of a theory, check page 29. Every experiment must have at least one independent variable (what the experimenter controls) and at least one dependent variable (what the experimenter measures). Blind observers provide an advantage.

The correlation between students' grades and their scores on a self-esteem questionnaire is very low, not much above 0. Why might that be?

One possibility is that grades are unrelated to self-esteem. Another possibility is that we used an inaccurate measurement of either self-esteem or grades or both. If anything is measured poorly, it cannot correlate strongly with anything else.

On average, the more medicines people take, the more likely they are to die young. Propose alternative explanations for this correlation.

Perhaps people get sick from complications caused by taking too many pills. Or maybe the people who take many medicines are those who already had serious illnesses.

On average, drug addicts who regularly attend counseling sessions are more likely to stay drug-free than those who drop out. Propose alternative explanations for this correlation.

Perhaps the counseling sessions are helpful to people who want to quit drugs. Or perhaps the people with the most serious addictions are the ones who quit.

People who awaken frequently during the night are more likely than other people to feel depressed.

Positive correlation between awakenings and depression.

Suppose a new performer demonstrates what appears to be an amazing ability to read people's minds or predict the future. Before anyone investigates, why do scientists assume it is more likely to be a trick than a supernatural power?

Scientists prefer the more parsimonious explanation. They resist an extraordinary conclusion if they can find a simpler one.

An instructor wants to find out whether the frequency of testing in an introductory psychology class influences students' final exam performance. The instructor gives weekly tests in one class, just three tests in a second class, and only a single midterm exam in the third class. All three classes take the same final exam, and the instructor then compares their performances. Identify the independent variable and the dependent variable in this experiment.

The independent variable is the frequency of tests during the semester. The dependent variable is the students' performance on the final exam.

Which indicates a stronger relationship between two variables, a +0.50 correlation or a −0.75 correlation?

The −0.75 correlation indicates a stronger relationship—that is, a greater accuracy of predicting one variable based on measurements of the other. A negative correlation is just as useful as a positive one.

Suppose you stand on a street and you interview every 10th person who walks by. What kind of sample is this—convenience, representative, or random?

This is a convenience sample. You made no effort to get a sample that matches the total population in age or anything else, so it is not a representative sample. Everyone in the population did not have an equal chance of participating, because not all kinds of people are equally likely to be walking down that street at that time of day.

Suppose we find a 0.8 correlation between students' reported interest in psychology and their grades on a psychology test. What conclusion can we draw?

We can conclude only that if we know either someone's interest level or test score, we can predict the other with reasonably high accuracy. We cannot conclude that an interest in psychology will help someone learn the material or that doing well on psychology tests increases someone's interest in the material. Either conclusion might be true, of course, but neither conclusion follows from these results. A correlational study cannot demonstrate a cause-and-effect relationship.

What would you propose as an operational definition of sense of humor?

We might define sense of humor as the number of times someone laughs during a movie or the number of times someone says something that makes other people laugh. Other definitions are possible if they include a method of measurement.

People with high IQ scores are neither more nor less likely than other people to have high telephone numbers.

Zero correlation between telephone numbers and IQ scores.

Of the following correlation coefficients, which one indicates the weakest relationship between two variables—that is, the lowest accuracy of using one variable to predict the other one? a. 0 b. +0.5 c. −0.75

a. 0

Consider the following distribution of scores: 6, 4, 17, 1, 10, 4, 14, 4, 12.The mean is , the median is , and the mode is . a. 8 ... 6 ... 4 b. 8 ... 10 ... 4 c. 6 ... 8 ... 4 d. 4 ... 6 ... 8

a. 8...6...4

Why is an anecdote not considered strong evidence? a. An anecdote is not replicable. b. An anecdote is not falsifiable. c. An anecdote is observed in a double-blind manner. d. An anecdote is part of an experiment.

a. an anecdote is not replicable.

It has been reported that people who spend more time reading tend to have a larger vocabulary. This conclusion is probably based on which kind of study? a. Correlation b. Double-blind experiment c. Cross-cultural study d. Single-blind experiment

a. correlation

An elementary school tests whether physical exercise influences children's performance. Children in each class are randomly assigned to physical exercise or movie watching for 30 minutes each afternoon. All children take the same tests, and the instructors compare their performances. The independent variable is , and the dependent variable is . a. exercise versus movie watching ... scores on tests b. scores on tests ... the number of students in each class c. the number of students in each class ... exercise versus movie watching d. scores on tests ... exercise versus movie-watching

a. exercise versus movie watching... scores on tests

Which of the following do researchers generally regard as desirable? a. Falsifiable theories b. Demand characteristics c. Experimenter bias d. Illusory correlations

a. falsifiable theories

Which of these procedures produces a random sample of the students in your class? a. Interview all the students whose telephone numbers end with 3. b. Interview the first person in each row. c. Interview the last 10 people who show up for class. d. Interview anyone who is willing to volunteer.

a. interview all the students whose telephone numbers end with 3

Suppose someone reports that blood levels of a certain chemical are negatively correlated with aggressive behavior. What does that mean? a. The higher the level of that chemical, the lower the probability of aggression. b. The lower the level of that chemical, the lower the probability of aggression. c. Levels of that chemical have no consistent relationship to the probability of aggression. d. As people grow older, that chemical declines and so does the probability of aggression.

a. the higher the level of that chemical, the lower the probability of aggression

Which of the following could be an operational definition of political activism? a. The number of hours one has devoted to political campaigns b. A tendency to read about political issues and discuss them c. Willingness to stick to one's own political opinion even when friends disagree d. A set of firm and well considered opinions on political issues

a. the number of hours one has devoted to political campaigns

Which of the following could be an operational definition of "sadness"? a. The number of tears shed during a day b. The emotional outcome after someone has felt an important loss c. An inability to experience joy or laughter d. A general feeling of discouragement or despair

a. the number of tears shed during a day

A survey reports how many people say they have done something dishonest at work. Before we can interpret these results, what do we need to know? a. What were they told to count as an example of a dishonest act? b. What other faults did the people admit to doing? c. Why did someone decide to ask about dishonesty? d. Did the survey include equal numbers of men and women?

a. what were they told to count as an example of a dishonest act?

Suppose many researchers have conducted similar studies, but most used only a small number of participants. To estimate the true size of the results, which procedure would be best? a. A statement of parsimony. b. A meta-analysis. c. A survey. d. A correlation coefficient.

b. a meta-analysis.

Why do researchers use operational definitions of their terms? a. An operational definition explains the practical importance of something. b. An operational definition enables researchers to measure something. c. An operational definition explains the term to the average person. d. An operational definition provides a scientific explanation of something.

b. an operational definition enables researchers to measure somethings.

Which of the following is undesirable for psychological research and theories? a. Parsimony b. Demand characteristics c. Independent variables d. Falsifiable hypotheses

b. demand characteristics

Which of the following is an operational definition of ambition? a. A desire to get ahead in life b. The number of times one has applied for a new or better job c. Setting high goals and trying to achieve them d. The ability to overcome obstacles and persist until succeeding at some task

b. the number of times one has applied for a new or better job

Suppose some researcher reports a low correlation between stress and depression. One possible explanation is that stress had little to do with depression in that researcher's sample of the population. What is another possible explanation for these results? a. The people varied widely in their level of stress. b. The researcher made inaccurate measurements of either stress or depression. c. People with great stress are likely to become depressed. d. Depression is more common in some countries than in others.

b. the researcher made inaccurate measurements of either stress or depression

What does it mean to say that a theory is "falsifiable"? a. Research has contradicted the theory. b. We can imagine results that would contradict the theory. c. Most people disagree with the theory. d. People are still debating whether the theory is correct.

b. we can imagine results that would contradict the theory.

The "Yes-ists" claim there are intelligent beings somewhere in outer space. The "No-ists" claim there are not. Which side has the burden of proof, and why? a. Someone who is defending the more popular beliefs or values b. Someone who is suspected of being dishonest c. Someone who should be in the better position to provide convincing evidence d. Someone who is proposing a more parsimonious explanation

c. someone who should be in the better position to provide convincing evidence.

If someone publishes surprising but incorrect results, in the long run people will not take the study seriously. Why not? a. The interpretation will not be parsimonious. b. The hypothesis will not be plausible. c. The results will not be replicable. d. The methods will not be explained in enough detail

c. the results will not be replicable.

On average, old people who read more books are less likely to develop Alzheimer's disease. What conclusion can we draw from this result? a. Reading books tends to prevent Alzheimer's disease. b. People who are already starting to develop Alzheimer's disease don't read many books. c. We can draw neither of these conclusions.

c. we can draw neither of these conclusions

On average, students who attend class every day get better grades than those who frequently miss. Which conclusion, if any, can we draw from this result? a. Attending class helps people improve their grades. b. Brighter students, who are likely to get good grades, are more likely than average to attend class conscientiously. c. We can draw neither of these conclusions.

c. we can draw neither of these conclusions

Of the following, which would be the most important step in evaluating the accuracy of Nostradamus's predictions? a. Take several predictions that someone claims to have been correct. Ask a large number of people to evaluate whether they seem to be correct. b. Count what percentage of his predictions seems to have come true and what percentage has not. c. Compare the percentage of his predictions that seems to have come true to the percentage for other people who claim to have psychic powers. d. Ask proponents of his predictions to state predictions of events before they happen. Then see how many come true, as compared to the percentage we could expect to come true by accident.

d. Ask proponents of his predictions to state predictions of events before they happen. Then see how many come true, as compared to the percentage we could expect to come true by accident.

It seems that it always rains when you wanted to go camping. However, you never kept any systematic records. The apparent relationship is probably an example of what? a. A double-blind study b. A significant negative correlation c. A significant positive correlation d. An illusory correlation

d. an illusory correlation

Which research method generally uses the fewest participants? a. Survey b. Correlation c. Single-blind experiment d. Case history

d. case history

A double-blind study helps alleviate the problems caused by which of the following? a. Falsifiability b. Independent variables c. Failure to replicate a study d. Demand characteristics

d. demand characteristics

Suppose you interview every tenth person who enters a shopping mall one day. What kind of sample is this? a. It is a cross-cultural sample. b. It is a random sample. c. It is a representative sample. d. It is a convenience sample.

d. it is a convenience sample

What is one way in which psychological research differs from chemistry and other sciences? a. Unlike psychologists, chemists use the experimental method. b. Unlike psychologists, chemists analyze their results with statistics. c. Psychological experimentation dates back to the time of the ancient Greeks. d. Psychological research faces more serious ethical restraints.

d. psychological research faces more serious ethical restraints

We should be more impressed with a result if the 95 percent confidence intervals are . We should be more impressed with a result if the p value is . a. large ... large b. large ... small c. small ... large d. small ... small

d. small...small

In science and in a criminal trial, who has the "burden of proof"—that is, the obligation to demonstrate that its claims are correct? a. The side that has more to lose b. The side defending the more popular point of view c. The side defending the more interesting theory d. The side that should be able to produce good evidence, if they are right

d. the side that should be able to produce good evidence, if they are right

Suppose researchers find a +0.4 correlation between the number of vitamin pills people take and their mental health. Which conclusion, if any, can we draw from this result? a. Taking vitamin pills improves mental health. b. Strong mental health improves people's probability of taking action to maintain health. c. Wealthier people are more likely than average to take vitamin pills, and also to be mentally healthy. d. We can draw none of these conclusions.

d. we can draw none of these conclusions

For the following distribution of scores, determine the mean, the median, and the mode: 5, 2, 2, 2, 8, 3, 1, 6, 7.

mean = 4; median = 3; mode = 2. b. mean = 7; median = 3; mode = 2.