PSY310 : Chap. 10

Variability in DV scores that is due to the effects of the IV is known as __________ variability. a.between-groups b.error c.within-subjects d.degrees of freedom

a. between-groups

What is the principle of parsimony?

The belief that explanations of phenomena and events should remain simple until the simple explanations are no longer valid

We use _________ assignment whenever there is a relationship between the participants in the groups. a.random b.correlated c.confounded d.experimental

b. correlated

Roger conducts an experiment in which some participants receive therapy and others do not. The people who receive therapy are referred to as the _______ group, and the people who do not receive therapy are referred to as the ________ group. a.control; experimental b.experimental; control c.independent; dependent d.dependent; independent

b. experimental; control

What are the two primary advantages of correlated-groups designs? a.control issues and statistical issues b.random assignment and control issues c.random assignment and statistical issues d.control issues and heterogeneity of variance issues

a. Control issues and statistical issues

Which of the following is an advantage of correlated-groups designs? a.Correlated-groups designs help to control participant (subject) variables. b.Correlated-groups designs are better than independent-groups designs when the researcher cannot remove the effects of the IV. c.Correlated-groups designs use random assignment and independent-groups designs do not. d.All of the above are advantages of correlated-groups designs.

a. Correlated-groups designs help to control participant (subject) variables.

When we randomly assign our participants to groups, we create a.independent groups. b.matched pairs. c.natural pairs. d.All of the above.

a. independent groups

With ________ assignment, we equate groups on a specific variable, and with _______ assignment, we leave the equating process to chance. With ________ assignment, we equate groups on a specific variable, and with _______ assignment, we leave the equating process to chance. a.matched; random b.statistical; matched c.random; matched d.matched; statistical

a. matched; random

When researchers cannot remove the effect of an IV, they are NOT likely to choose which type of research design? a.repeated measures b.matched pairs c.between-subjects d.natural pairs

a. repeated measures

When we test participants more than once, we are using a a.repeated measures design. b.between-subjects design. c.matched pairs design. d.natural pairs design.

a. repeated measures design.

A ______ test can tolerate violations of its assumptions and still provide accurate answers. a.robust b.parsimonious c.heterogeneous d.homogenous

a. robust

If you only have a small number of participants available, you should use which type of assignment to groups? a.random assignment b.correlated assignment c.independent assignment d.Both (a) and (c) are correct.

b. Correlated Assignment

Research participants in a two-group design who are measured and equated on some variable before the experiment are referred to as a.repeated measures pairs. b.matched pairs. c.natural pairs. d.between-subjects pairs.

b. Matched pairs.

A researcher has pairs of rat littermates and always assigns one littermate to the experimental group and one littermate to the control group. This researcher is using a.matched pairs. b.natural pairs. c.repeated measures pairs. d.between subjects pairs.

b. Natural pairs.

In an experiment, the FEWEST number of independent variables that you can have would be a.zero. b.one. c.two. d.Cannot determine without more information.

b. One

What is the most basic experimental design? a.The one-group design b.The two-group design c.The three-group design d.The 2 x 2 design

b. The two-group design

In a ___________ design, participants serve as their own controls. a.between-subjects b.natural pairs c.repeated measures d.matched pairs

c. repeated measures

Tim measured classroom behaviors both before and after administering a family systems intervention to a sample of children. Tim used a(n) _________ design and should analyze his data using a(n) _____________ samples t test. a.matched pairs; correlated b.repeated measures; independent c.repeated measures; correlated d.between-subjects; independent

c. repeated measures; correlated

Random ___________ deals with choosing your research participants, whereas random _________ deals with putting those participants into groups. a.assignment; selection b.comparison; assignment c.selection; assignment d.selection; comparison

c. selection; assignment

When we compare groups of participants who were assigned to groups through matched pairs, natural pairs, or repeated measures, we are using a a.between-subjects comparison. b.random assignment comparison. c.within-subjects comparison. d.control-subjects comparison.

c. within-subjects comparison.

Why does using a correlated-groups design reduce error variability? a.The independent variable is stronger in a correlated-groups design than in a between-subjects design. b.The dependent variable is stronger in a correlated-groups design than in a between-subjects design. c.The correlated-groups design is better suited to multiple independent variables compared to the between-subjects design. d.Error variability due to individual differences in participants is decreased in a correlated-groups design.

d. Error variability due to individual differences in participants is decreased in a correlated-groups design.

The general plan for selecting participants, assigning them to conditions, controlling extraneous variables, and gathering data is known as the ____________ design. a.control group b.repeated measures c.statistical d.experimental

d. Experimental

Which of the following is an advantage of independent-groups designs? a.Independent-groups designs have reduced error variability compared to correlated-groups designs. b.Independent-groups designs have more statistical power than correlated-groups designs. c.Independent-groups designs have fewer degrees of freedom than correlated-groups designs. d.Independent-groups designs are easier to plan and execute than correlated-groups designs.

d. Independent-groups designs are easier to plan and execute than correlated-groups designs.

In a _______ design, we generally have greater certainty regarding the equality of the groups before the experiment begins than with a _______ design. a.between-subjects; correlated groups b.positively correlated; negatively correlated c.negatively correlated; positively correlated d.correlated-groups; between-subjects

d. correlated-groups; between-subjects

In a correlated-groups design, error variability due to individual differences _________, which makes it ________ to find a significant effect. a.increases; harder b.increases; easier c.decreases; harder d.decreases; easier

d. decreases; easier

A researcher ________ manipulate an independent variable in ex post facto research; therefore, we ______ draw cause-and-effect conclusions. a.does; can b.does not; can c.does; cannot d.does not; cannot

d. does not; cannot

Candace compares the reaction times of people diagnosed with obsessive-compulsive disorder and people not diagnosed with obsessive-compulsive disorder. Candace has conducted a(n) a.within-subjects study. b.matched pairs study. c.true experiment. d.ex post facto research study.

d. ex post facto research study.

In a two-group design, the group of participants that receives the IV is referred to as the ________ group, and the group of participants that does not receive the IV is referred to as the _________ group. a.independent; dependent b.dependent; independent c.control; experimental d.experimental; control

d. experimental; control

The Fmax statistic is used to test the assumption of a.equality of groups. b.the principle of parsimony. c.non-confounded experiments. d.homogeneity of variance.

d. homogeneity of variance.

Burkley et al. (2000) conducted a study in which half of the consent forms had a "right to withdraw" statement and the other half didn't. What kind of design would NOT be appropriate for this study? a.matched pairs design. b.between-subjects design. c.natural pairs design. d.repeated measures design.

d. repeated measures design.

Random assignment works best when a.there are three or more groups instead of two. b.the researcher can match participants on some predetermined variable. c.there are multiple dependent variables. d.the sample size is large.

d. the sample size is large

The assumption that the variances are equal for the groups you plan to compare statistically is known as a.the principle of parsimony. b.homogeneity of variance. c.heterogeneity of variance. d.within-subjects variance.

b. homogeneity of variance.

When the number of observations in each group is equal, the critical t value in a correlated groups design is ________ the critical t value in an independent-groups design. a.the same as b.larger than c.smaller than d.always three points greater than

b. larger than

Which of the following represents the general formula for statistical tests? a.error variability / between-groups variability b.within-groups variability / error variability c.error variability / within-groups variability d.between-groups variability / error variability

d. Between-groups variability / error variability

Variability in DV scores that is due to factors other than the IV is known as _________ variability. a.degrees of freedom b.between-groups c.error d.within-subjects

c. error

Bruce compared men and women on the number of errors they made on a test. Bruce used a(n) _________ and should analyze his data using a(n) ____________. a.true experiment; independent samples t test b.true experiment; correlated samples t test c.ex post facto design; independent samples t test d.ex post facto design; correlated samples t test

c. ex post facto design; independent samples t test

A research approach in which the experimenter cannot directly manipulate the IV but can only measure an IV because it is predetermined is known as a(n) a.case study. b.true experiment. c.ex post facto research design. d.participant observation.

c. ex post facto research design.

The ________ variable is manipulated by the researcher, and the ________ variable is the response or behavior that the researcher measures. a.extraneous; independent b.extraneous; dependent c.independent; dependent d.dependent; independent

c. independent; dependent

A correlated-groups design reduces error variability by reducing error due to a.measurement errors. b.extraneous variation. c.individual differences. d.All of the above.

c. individual differences.

The goal in an experiment is to __________ the between-groups variability and ___________ the error variability. a.maximize; maximize b.minimize; minimize c.maximize; minimize d.minimize; maximize

c. maximize; minimize

Error variability consists of a.individual differences. b.measurement errors. c.extraneous variation. d.All of the above.

d. All of the above.

Independent variables can a.contrast the presence versus the absence of some variable. b.contrast "high" versus "low" amounts of some variable. c.be measured rather than manipulated in an ex post facto design. d.All of the above.

d. All of the above.

Which of the following is NOT a practical consideration for repeated measures designs? a.Can we measure our DV more than once? b.Can our participants cope with repeated testing? c.Can we remove the effects of the IV? d.Can we use more than one IV?

d. Can we use more than one IV?

________ statistical values are associated with significant differences in your experiment. a.Extra-small b.Small c.Medium d.Large

d. Large

Which of the following is NOT associated with a within-subjects comparison? a.Natural pairs b.Matched pairs c.Repeated measures d.Random assignment

d. Random assignment

Suppose you know that you would like to conduct an experiment with two groups, an experimental group and a control group. What is the next question that you face? a.Should I use a t test or an ANOVA? b.Should I have more than one independent variable? c.Should I do an experiment or a correlational study? d.Should I use an independent groups design or a correlated groups design?

d. Should I use an independent group design or a correlated groups design

Which of the following is a limitation of the ex post facto design? a.Participants who are exposed to the DV multiple times can become sensitized to the area under investigation. b.Experimenter bias is a greater problem in ex post facto research compared with other research designs. c.It is difficult to find natural pairs. d.You cannot be certain that the IV is the only difference between groups.

d. You cannot be certain that the IV is the only difference between groups.

Beth is interested in studying the effects of movies on peoples' attitudes toward the mentally ill. She obtains a sample of college students who have never seen One Flew Over the Cuckoo's Nest. Half of the students watch the movie and half do not, and then she measures their attitudes toward the mentally ill. She is worried that if participants have a loved one who is mentally ill, they may have different attitudes from everyone else. She decides to give a pretest to determine if people have family members with a mental illness to make sure that there are equal numbers of such people in both the experimental and control groups. Beth is using a.repeated measures. b.random assignment. c.natural pairs. d.matched pairs.

d. matched pairs.

Research participants in a two-group design who are naturally related in some way (e.g., twins) are referred to as a.matched pairs. b.repeated measures pairs. c.between subjects pairs. d.natural pairs.

d. natural pairs.

Suppose you conducted an experiment with 20 participants in each group. You would have _____ degrees of freedom in an independent-groups design and _____ degrees of freedom in a correlated-groups design. a.38; 19 b.19; 38 c.20; 20 d.18; 19

a. 38; 19

Suppose you know that you would like to conduct a study with one independent variable. What is the next question that you face? a.How many groups will my IV have? b.What type of participant groups do I have? c.Should I use a t test for independent samples or a t test for correlated samples? d.Should I use matched pairs, repeated measures, or natural pairs?

a. How many groups will my IV have

Which of the following is NOT a way to use correlated assignment? a.Random selection b.Matched pairs c.Repeated measures d.Natural pairs

a. Random Selection

When is the best time to choose your statistical analysis? a.before data collection b.during data collection c.after data collection d.it doesn't matter

a. before data collection

The differing amounts of the IV are referred to as a.within-groups variability. b.levels. c.correlations. d.repeated measures.

b. Levels

The belief that explanations should remain simple until the simple explanations are no longer valid is known as the principle of a.variability. b.parsimony. c.repeated measures. d.independent samples.

b. Parsimony

Why is random assignment important? a.Random assignment ensures that the groups are matched on some variable before the experiment. b.Random assignment helps to make the groups equal on a variety of variables. c.Random assignment ensures that each member of the population has an equal chance of being chosen to be in the experiment. d.Random assignment increases the test-retest reliability of the experiment.

b. Random assignment helps to make the groups equal on a variety of variables.

Which of the following is the most parsimonious experimental design? a.The one-group design b.The two-group design c.The three-group design d.The 2 x 2 design

b. The two-group design

When we compare groups of participants who were randomly assigned to groups, we are making a a.within-subjects comparison. b.between-subjects comparison. c.correlated-subjects comparison. d.matched-subjects comparison.

b. between-subjects comparison

Bernice conducts a study on the effects of violent television on children. She obtains a sample of 30 aggressive children and 30 non-aggressive children. She has the aggressive children watch 15 minutes of aggressive television and the non-aggressive children watch 15 minutes of non-aggressive television. This study represents a _________ study. a.correlational b.confounded c.within-subjects d.All of the above.

b. confounded

When the variances of the two groups are not comparable, we have a.homogeneity of variance. b.heterogeneity of variance. c.between-groups variance. d.within-groups variance.

b. heterogeneity of variance.

Samantha had one group of participants watch a violent hockey game and had the other group watch a nonviolent hockey game. She pretested participants on their levels of trait aggressiveness to make sure there were equal numbers of such people in both groups. She measured physiological arousal in response to the game. Samantha used a(n) ________ design and should analyze her data using a(n) __________ samples t test. a.natural pairs; correlated b.matched pairs; correlated c.between-subjects; independent d.matched pairs; independent

b. matched pairs; correlated

Elliot conducts a study with one experimental group and one control group. Elliot has _______ independent variable(s) with _______ group(s). a.zero; two b.one; two c.two; zero d.two; one

b. one; two

A method of assigning research participants to groups so that each participant has an equal chance of being in any group is known as a.random selection. b.random assignment. c.between-subjects assignment. d.correlated assignment.

b. random assignment

Frances wishes to study the effects of violent videogames on children's levels of aggression. As children come to the lab for the study, she flips a coin. If it turns up heads, the child plays a violent videogame. If it turns up tails, the child plays a nonviolent videogame. Frances has used the technique of a.random selection. b.random assignment. c.creating matched pairs. d.correlated assignment.

b. random assignment

When each member of the population has an equal chance of being chosen for an experiment, the researcher has used a.random assignment. b.random selection. c.convenience sampling. d.balancing.

b. random selection

Certain dependent variables, such as solving puzzles and completing mazes, are difficult to administer more than once. For these research projects, researchers typically avoid which kind of design? a.matched pairs b.repeated measures c.between-subjects d.natural pairs

b. repeated measures

Random assignment controls ________ extraneous variables. a.known b.unknown c.correlated-groups d.ex post facto

b. unknown

You should use a correlated samples t test when a.you have a three-group design, you randomly assigned your participants, and your DV is measured on an interval or ratio scale of measurement. b.you have a two-group design, you used matched pairs, and your DV is measured on an interval or ratio scale of measurement. c.you have a two-group design, you randomly assigned your participants, and your DV is measured on a nominal or ordinal scale of measurement. d.you have a two-group design, you randomly assigned your participants, and your DV is measured on an interval or ratio scale of measurement.

b. you have a two-group design, you used matched pairs, and your DV is measured on an interval or ratio scale of measurement.

In an experiment that involves two groups, there is/are _____ source(s) of variability. a.No b.1 c.2 d.3

c. 2

Which of the following is a similarity between the two independent-groups design and the two correlated-groups design? a.Both designs involve two independent variables. b.Both designs involve the same kind of assignment to groups. c.Both designs involve one independent variable with two groups. d.Both designs involve a correlational design rather than an experimental design.

c. Both designs involve one independent variable with two groups.

Undesired variables that may influence the DV and thus invalidate the experiment are known as _________ variables. a.independent b.dependent c.extraneous d.parsimonious

c. Extraneous

Degrees of freedom in the two-correlated groups design are _______, and degrees of freedom in the two-independent groups design are _________. a.N - 1; N - 1 b.N - 2; N - 2 c.N - 1; N - 2 d.N - 2; N - 1

c. N - 1; N - 2

Which of the following considerations is MOST important when using matched pairs? a.The researcher should make sure to use biologically related participants to create matched pairs. b.The researcher should make sure to have a large enough sample size to increase the chances that random assignment will be successful. c.The researcher should make sure to match on a variable that will affect the dependent variable. d.All of the above are important considerations for matched pairs.

c. The researcher should make sure to match on a variable that will affect the dependent variable.

Jamonn conducts a study in which one group of participants is randomly assigned to be in a 70-degree room, and another group of participants is randomly assigned to be in a 90-degree room. Jamonn will make a a.within-subjects comparison. b.matched-subjects comparison. c.between-subjects comparison. d.correlated-subjects comparison.

c. between-subjects comparison

Julie measures participants' anxiety levels before treatment and again after treatment. Julie is using a ____________ design. a.between-subjects b.natural pairs c.matched pairs d.repeated measures

d. repeated measures

An experiment in which the experimenter directly manipulates the IV is known as a(n) a.ex post facto research design. b.participant observation. c.correlational research design. d.true experiment.

d. true experiment.

You should use an independent samples t test when a.you have a two-group design, you used matched pairs, and your DV is measured on an interval or ratio scale of measurement. b.you have a two-group design, you randomly assigned your participants, and your DV is measured on a nominal or ordinal scale of measurement. c.you have a three-group design, you randomly assigned your participants, and your DV is measured on an interval or ratio scale of measurement. d.you have a two-group design, you randomly assigned your participants, and your DV is measured on an interval or ratio scale of measurement.

d. you have a two-group design, you randomly assigned your participants, and your DV is measured on an interval or ratio scale of measurement.