Research Methods Exam #3

Suppose you earned an 80 on an exam. The class mean was 82 with SD = 2. Your exam score is

1 SD below the mean

Suppose exam scores are normally distributed with M = 80 and SD = 5. Approximately what percentage of scores fall between the scores of 75 and 85?

68.26%

If our statistical result was significant, what is the value of calculating effect size?

A significant statistical test tells us that the IV had an effect, and the effect size tells us about the size of the significant effect.

Researchers use which of the following to choose their participants?

All of the above

Which of the following answers identifies the independent variable (IV) and dependent variable (DV) for the following example: Relations between toddlers' vocabulary development and watching Sesame Street while eating a snack

DV= vocabulary development, IV= watching Sesame Street

The ___________ statistics summarize numbers and _____________ statistics determine whether the results are significant.

Descriptive; inferential

Which of the following is a factor regarding how many participants a researcher will test?

Finances, Availability, Finances (All of the above)

__________ refers to events that occur between repeated measurements of the dependent variable.

History

Which of the following answers identifies the independent variable (IV) and dependent variable (DV) for the following example: Hypnosis used to quit smoking among adolescents and adults

IV=Hypnosis, DV=quitting smoking

Which of the following answers identifies the independent variable (IV) and dependent variable (DV) for the following example: The effects of swimming training on Mr. Toad's lung capacity during two races.

IV=swimming training, DV=lung capacity

Which of the following answers identifies the independent variable (IV) and dependent variable (DV) for the following example: Tutoring in spelling and grammar and grades in English for students whose native language is Spanish

IV=tutoring in spelling and grammar, DV=grades in English

Why do the groups have to be equivalent at the start of an experiment?

If the groups are not equivalent at the start of an experiment, we cannot be certain that the IV caused any difference observed in the DV.

The variance and standard deviation are based on how much each score deviates from the

Mean

Gary conducts a study to examine the effectiveness of an exercise program on weight loss. The experimental group must exercise for two hours per day for six months. The control group must exercise for 15 minutes per day for six months. Gary finds greater weight loss in the experimental group than the control group. Unfortunately, 60% of the participants in the experimental group dropped out of the study, compared to 10% of the control group participants. Gary has encountered what kind of problem?

Mortality

When the position of a treatment in a series determines, in part, the participants' responses, the researcher is dealing with

Nuisance; extraneous

Why are participant characteristics not true independent variables?

Participant characteristics are not manipulated by the researcher.

Consider the following scores: X Y 8 9 3 4 5 5 1 2 4 2 7 9 These scores depict a ________ correlation

Positive

What is the main drawback of randomization?

The researcher cannot be sure that all extraneous variables have been equally distributed across the groups.

Why are extraneous variables problematic?

The researcher does not know if the results are due to the independent variable or to the extraneous variables.

Why is it important to understand scales of measurement?

The scale of measurement for the dependent variable determines the kind of statistical test that can be conducted.

Which of the following is NOT a technique used by researchers to control demand characteristics?

Use a general population sample rather than a college student sample

How spread out the scores are refers to

Variability

Under what circumstances should you calculate the median instead of the mean?

When there are a limited number of extreme scores in the distribution.

In what way does culture influence the research process?

all of the above

Which of the following is a common method for controlling physiological and psychological experimenter effects?

all of the above

An extraneous variable influences the difference __________ groups.

between

The tendency of a particular culture to respond in a certain manner is known as a(n)

cultural response set.

An industrial-organizational psychologist is hired to help increase productivity at a company. He teaches one group of workers strategies to improve productivity and has a control group who does not learn the new strategies. However, workers in the experimental group talk to their friends in the control group about the new strategies, and pretty soon everyone is using them. Which kind of problem has the psychologist encountered?

diffusion of treatment

When the effects of amount or type of previous training or learning are manipulated, the researcher is using a(n) __________ independent variable.

experience

Demand characteristics act as ________ variables when participants know which group they are in, and demand characteristics act as _________ variables when participants are not sure which group they are in.

extraneous; nuisance

Exhibiting a high degree of control over the experiment _________ internal validity and __________ external validity.

increases; decreases

When a pretest sensitizes participants to the treatment yet to come, researchers have a problem of

interaction of testing and treatment

What is the most important property of any experiment?

internal validity

Directional hypotheses are associated with _____ tests and nondirectional hypotheses are associated with _______ tests.

one-tailed; two-tailed

Which of the following threats to external validity is the most difficult to deal with as a researcher?

participant-related threats

Which of the following is the BEST guideline for choosing the number of participants to use in a research project?

past research

A researcher is interested in creating equivalent groups in her experiment. If potential extraneous variables are unknown she should use _________, and if the extraneous variables are known she should use __________.

randomization; balancing

Dependent variable measurements that actually change the dependent variable being measured are known as

reactive measures.

George creates a new happiness scale and gives it to a sample of college students twice. Scores were consistent over time, which means that George's scale is

reliable.

Maturational changes are most likely to occur in an experiment that has

repeated measurements of the dependent variable.

When the experimental context or testing situation influences the participants' responses, it is known as a(n)

response set.

Within-_______ counterbalancing refers to the presentation of different treatment sequences to the same participant, and within-_________ counterbalancing refers to the presentation of different treatment sequences to different participants.

subject; group

The tendency for participants to behave as they perceive the experimenter wants them to behave is known as

the good participant effect.