Chapter 2A Scientific Methods in Psychology

Chapter 2A Scientific Methods in Psychology

Chapter 2A—Scientific Methods in Psychology

TRUE/FALSE

1.If a result is replicable, other investigators can repeat the procedure and get similar results.

ANS:TREF:replicableOBJ:remembering (definition)

2.If a result is not replicable, theorists will ignore it.

ANS:TREF:replicableOBJ:remembering

3.A meta-analysis allows someone to combine results from many studies as if they were one large study.

ANS:TREF:replicableOBJ:remembering

4.A scientific theory is no more than a guess.

ANS:FREF:theoryOBJ:remembering

5.A good scientific theory should be falsifiable.

ANS:TREF:burden of proofOBJ:remembering

6.If someone makes an interesting claim, such as extrasensory perception, anyone who doubts it has the “burden of proof.”

ANS:FREF:burden of proof

OBJ:application and understanding

7.Other factors being equal, theories that are the most parsimonious are preferred by scientists.

ANS:TREF:parsimonyOBJ:remembering

8.Several laboratory demonstrations of extrasensory perception are consistently replicable.

ANS:FREF:extrasensoryOBJ:remembering

9.Claims for extrasensory perception are neither parsimonious nor replicable.

ANS:TREF:extrasensoryOBJ:remembering

10.Most dictionary definitions are operational definitions.

ANS:FREF:operational def

OBJ:application and understanding

11.An operational definition tells how to measure something.

ANS:TREF:operational defOBJ:remembering (definition)

12.If you survey everyone you meet at the mall one day, you obtain a random sample of the population.

ANS:FREF:samplesOBJ:application and understanding

13.Changing the wording of a survey question causes many people to answer differently.

ANS:TREF:surveyOBJ:remembering

14.A correlation coefficient of -.7 represents a stronger relationship between variables than a correlation coefficient of +.5.

ANS:TREF:correlationOBJ:application and understanding

15.Dr. Jones finds a correlation of +.5 between variables A and B. Dr. Jones can logically conclude that changes in variable A caused the changes observed in variable B.

ANS:FREF:correlation/causation

OBJ:application and understanding

16.Properly conducted experiments allow researchers to draw conclusions about cause and effect.

ANS:TREF:experimentsOBJ:remembering

17.Every experiment has at least one independent variable.

ANS:TREF:experimentsOBJ:remembering

18.In an experiment on how watching violent television affects behavior, the type of television program viewed would be the dependent variable.

ANS:FREF:experimentsOBJ:application and understanding

19.The control group in an experiment is the group of people who have some control over what happens.

ANS:FREF:experimentsOBJ:remembering (definition)

20.Random assignment is an important procedure in both experiments and correlational research.

ANS:FREF:correlationOBJ:application and understanding

21.The use of a blind observer reduces the influence of experimenter bias.

ANS:TREF:blind studiesOBJ:application and understanding

22.A double-blind procedure reduces the influence of demand characteristics.

ANS:TREF:blind studiesOBJ:application and understanding

23.If most patients recover from depression after a few months of therapy, we can conclude that the therapy was helpful.

ANS:FREF:before/afterOBJ:application and understanding

24.A before-and-after study can lead to a firm conclusion, even without a control group.

ANS:FREF:before/afterOBJ:application and understanding

25.Any ethical experiment on people begins by asking participants for their informed consent.

ANS:TREF:human ethicsOBJ:remembering

26.The mean is especially useful if the scores approximate the normal distribution.

ANS:TREF:central scoreOBJ:application and understanding

27.Consider the following set of scores on a quiz: 2, 2, 3, 5, 8. The mean for this set of scores is 3.

ANS:FREF:central scoreOBJ:application and understanding

28.Consider the following set of scores on a quiz: 2, 2, 3, 5, 8. The mode for this set of scores is 2.

ANS:TREF:central scoreOBJ:application and understanding

29.Consider the following set of scores on a quiz: 2, 2, 3, 5, 8. The median for this set of scores is 4.

ANS:FREF:central scoreOBJ:application and understanding

30.Group A receives the following scores: 14, 15, 15, 15, 16. Group B receives the following scores: 4, 8, 12, 16, 20. The standard deviation for Group B is higher than it is for Group A.

ANS:TREF:variationOBJ:application and understanding

31.Professor Smith finds that the outcomes of his results are not statistically significant. Therefore, Professor Smith’s hypothesis was wrong.

ANS:FREF:inferentialOBJ:application and understanding

32.In general, the smaller the p value, the more impressive the results.

ANS:TREF:inferentialOBJ:application and understanding

33.If the p value of a research study is small, the 95% confidence intervals for each group will be large.

ANS:FREF:inferentialOBJ:application and understanding

COMPLETION

1.A statement that leads to a clear prediction is called a ______.

ANS:hypothesis

REF:hypothesisOBJ:remembering (definition)

2.The goal of scientific research is to establish comprehensive explanations of observable events. These explanations are called ______.

ANS:theories

REF:evaluating theoriesOBJ:remembering (definition)

3.If different researchers consistently get similar results, we say the results are ______.

ANS:replicable

REF:replicableOBJ:remembering (definition)

4.If a theory is stated so precisely that we can see what evidence would count against it, we say the theory is ______

ANS:falsifiable

REF:burden of proofOBJ:remembering (definition)

5.If a theory makes simple, acceptable assumptions, we say the theory is ______.

ANS:parsimonious

REF:parsimonyOBJ:remembering (definition)

6.Two serious objections to claims of extrasensory perception are that the explanations are not ______and that the results are not ______.

ANS:parsimonious; replicable

REF:extrasensoryOBJ:remembering

7.A definition that states how to measure something is a(n) ______definition.

ANS:operational

REF:operational defOBJ:remembering (definition)

8.If every individual in the population has an equal chance of being selected for a sample, the sample is said to be a/an ______sample.

ANS:random

REF:samplesOBJ:remembering (definition)

9.A researcher who wants to generalize the findings to apply to the whole population will, ideally, get what kind of sample? ______

ANS:

random sample

cross-cultural sample

REF:samplesOBJ:application and understanding

10.A sample of the population that matches the whole population in percentage of males and females, old and young, etc., is a(n) ______sample.

ANS:representative

REF:samplesOBJ:remembering (definition)

11.An instructor measures to what extent the students who attend class regularly also do well on the tests. This type of research is called a ______

ANS:a correlational study

REF:correlationOBJ:application and understanding

12.A correlation coefficient ranges from a low of zero to a high of ____

ANS:

1 (or “plus or minus 1”)

1 or “plus or minus 1”

1

plus or minus 1

REF:correlationOBJ:remembering

13.If an increase in one variable is not associated with any consistent increase or decrease in a second variable, then the correlation between the two variables is ______.

ANS:

zero

0

REF:correlationOBJ:remembering

14.To evaluate the effects of expectations, a researcher might give the experimental group a new drug and give the control group an inactive pill, known as a(n)______

ANS:placebo

REF:placeboOBJ:remembering

15.An experimenter manipulates one variable to see how it affects a second variable. The one the experimenter manipulates is the ______variable.

ANS:independent

REF:experimentsOBJ:remembering (definition)

16.An experimenter manipulates one variable to see how it affects a second variable. The one the experimenter measures to see how it was affected is the ______variable.

ANS:dependent

REF:experimentsOBJ:remembering (definition)

17.In a properly conducted experiment, the researcher assigns people to the experimental and control groups by a procedure known as ______assignment.

ANS:random

REF:experimentsOBJ:remembering

18.To reduce or avoid effects of experimenter bias, it is best to have a ______observer make the observations or collect the data.

ANS:blind

REF:blind studiesOBJ:application and understanding

19.In many cases a researcher conceals the purpose of the study, so that participants will not be heavily influenced by ______characteristics.

ANS:demand

REF:demand characteristicsOBJ:remembering

20.The main problem with a before-and-after study is that it has no ______group.

ANS:control

REF:before/afterOBJ:remembering

21.Before conducting any experiment on humans, a psychological investigator must obtain ______consent from the participants.

ANS:informed

REF:human ethicsOBJ:remembering

22.The sum of all the scores divided by the total number of scores is called the ______. (NOT “average.” Give the more precise term.)

ANS:mean

REF:central scoreOBJ:remembering (definition)

23.If you arrange scores from the highest to the lowest, the middle one is called the ______.

ANS:median

REF:central scoreOBJ:remembering (definition)

SHORT ANSWER

1.A scientist has formed the following hypothesis: individuals who eat a late lunch consume more food than individuals who eat an early lunch. Once she has constructed her hypothesis, what are the three steps that she should follow to complete her experiment? State the steps and give an example of how to complete each step.

ANS:

The first step is to devise a method to test the hypothesis. One way to test the effects of time of day on calorie consumption would be to ask participants to fast in the morning and have one group eat lunch at 11:00 a.m. and the other group eat lunch at 2:00 p.m.

The next step is to collect results. The scientist would first need to define the variable of interest. In this example, counting calorie consumption at each dining time would be one option.

The final step is to interpret the data and determine what the results mean. If the participants eating early lunch consume more calories, the scientist should either abandon or modify the original hypothesis. If the participants eating early lunch consume fewer calories (matching the prediction), investigators gain confidence in their hypothesis, and may consider other possible explanations.

REF:gathering evidenceOBJ:application and understanding

2.After defining the variables involved in a study, scientists have to identify individuals to study. The population is the group of individuals to whom we hope our conclusions will apply. Researchers generally hope that their conclusions will apply to a large population, such as all 5-year-olds or all people with schizophrenia. Because it is not practical to examine everyone in the population, researchers study a sample of people and assume that the results for the sample apply to the whole population. Briefly define the following types of samples: convenience sample, representative sample, random sample, and cross cultural sample.

ANS:

Convenience Sample: a group chosen because of its ease of study. An example is the use of college students taking a psychology course.

Representative Sample: closely resembles the population in its percentage of males and females, Blacks and Whites, young and old, city dwellers and farmers, or other characteristics that are likely to affect the results.

Random Sample: every individual in the population has an equal chance of being selected. For example, the researcher might take the census report for a state and try to contact 100 people, chosen at random from the list.

Cross-Cultural Sample: groups of people from at least two cultures, such as the United States and India.

REF:general principles of psychological disorderOBJ:remembering (definition)

3.Why are most psychological researchers skeptical of the idea of extrasensory perception?

ANS:

First, despite many attempts, no one has found evidence for extrasensory perception that is consistently replicable. Second, because the idea conflicts with basic principles of physics, researchers seek a more parsimonious explanation.

REF:evaluating scientific theoriesOBJ:evaluating

4.Describe an example of a negative correlation.

ANS:

A few examples: (1) The greater the number of days in a month spent exercising, the fewer the number of sick days used. (2) The more time someone practices golf, the lower the person’s golf score, on average. (3) On average, people who smoke more cigarettes have a shorter life expectancy. (4) The more times a student misses class, the lower the probable score on a test.

REF:observational research designsOBJ:application and understanding

5.A mother is attempting to minimize the number of times that her toddler pulls on his kitty's tail. She wants to assess whether different types of discipline have any effect on his behavior. For three weeks during the month, the mother gives the toddler one week of one specific type of discipline. One week the toddler receives time outs, one week he has a toy taken away, and one week he is told to clean the kitty's bowl for each kitty tail pull. At the end of each week, the mother tallies up the number of kitty tail pulls for the week. Identify the independent variable and the dependent variable.

ANS:

The independent variable is the discipline method. The dependent variable is the number of kitty tail pulls.

REF:experimentsOBJ:application and understanding

6.Falsifiability, independent variables, dependent variables, blind observers, and demand characteristics are all potential characteristics of an experiment. Which of these would an experimenter try to minimize or avoid, and why?

ANS:

An experimenter would try to minimize or avoid demand characteristics since these are cues that tell a participant what is expected of him or her and what the experimenter hopes to find. The experimenter would like the results to depend on the experimental manipulation rather than participants’ attempts to conform to the experimenter’s predictions.

REF:experimentsOBJ:evaluating

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