ch 10

Vocabulary

Analysis of variance (ANOVA)

A statistical procedure designed to compare the means of the dependent variable across the conditions of an experimental research design.

ANOVA summary table

A table that displays the ANOVA calculations including F and its associated p-value.

Between-groups variance

In ANOVA, a measure of the variability of the dependent variable across the experimental conditions.

Between-participants designs

Experiments in which the comparison of the scores on the dependent variable is between the participants in the different levels of the independent variable and each individual is in only one level.

Carryover

A situation that can occur in a repeated measures design when the effects of one level of the manipulation are still present when the dependent measure is assessed for another level of the manipulation.

Conditions

A term used to describe the levels of an experimental manipulation in one-way experimental designs, or the cells in a factorial design.

Control condition

The level of the independent variable in which the situation of interest was not created.

Counterbalancing

A procedure in which the order of the conditions in a repeated measures design is arranged so that each condition occurs equally of ten in each order.

Degrees of freedom (df )

The number of values that are free to vary given restrictions that have been placed on the data.

Eta (h)

The effect size measure in the ANOVA.

Experimental condition

The level of the in dependent variable in which the situation of interest was created.

Experimental manipulations

The independent variable, created by the experimenter, in an experimental design.

F

In the ANOVA, a statistic that assesses the extent to which the means of the experimental conditions differ more than would be expected by chance.

Latin square design

A repeated measures research design that is counterbalanced such that each condition appears equally often in each order and also follows equally often after each of the other conditions.

Levels

The specific situations created by the experimental manipulation.

Manipulation (Experimental manipulations)

The independent variable, created by the experimenter, in an experimental design.

One-way experimental design

An experiment that has one independent variable.

Random assignment to conditions

A method of ensuring that the participants in the different levels of the independent variable are equivalent before the experimental manipulation occurs.

Repeated-measures designs

Experiments in which the same people participate in more than one condition of an experiment, thereby creating equivalence, and the differences across the various levels are assessed within the same participants.

T test

A statistical test used to determine whether two observed means are statistically different. T is a special case of the F statistic.

Within-groups variance

A measure of the variability of the dependent variable across the participants within the experimental conditions in ANOVA.

within-participants (within-subjects) design

Experiments in which the same people participate in more than one condition of an experiment, thereby creating equivalence, and the differences across the various levels are assessed within the same participants.

1) Which of the following represents the null hypothesis about the means of the dependent variable in a one-way ANOVA with two levels?

A) The mean in level A is significantly correlated with the mean in level B.

B) The mean in level A is greater than the mean in level B.

C) The mean in level A is equal to the mean in level B.

D) The mean in level A is either greater than or less than the mean in level B.

C) The mean in level A is equal to the mean in level B.

2) Which of the following statements is true?

A) Neither the independent nor the dependent variables are measured in experimental research.

B) Only the dependent variable is measured in experimental research.

C) Both the independent and dependent variables are measured in experimental research.

D) Only the independent variable is measured in experimental research.

B) Only the dependent variable is measured in experimental research.

3) When conducting statistical analyses in an experimental design, in order to confirm the research hypothesis, the researcher hopes that which of the following is true?

A) The between-groups variance is greater than the within-groups variance.

B) The mean in the experimental condition is greater than the mean in the control condition.

C) The within-groups variance is greater than the between-groups variance.

D) The mean in the control condition is greater than the mean in the experimental condition.

A) The between-groups variance is greater than the within-groups variance.

4) Which of the following is NOT a disadvantage of repeated measures designs over between-participant designs?

A) The potential for carryover effects

B) The potential for practice and fatigue effects

C) The potential for lowered statistical power

D) The potential for guessing the hypothesis

C) The potential for lowered statistical power

5) The goal of random assignment to conditions is to

A) ensure that the participants are selected randomly from the population.

B) ensure that the independent variable occurs prior to the dependent variable.

C) select which individuals will receive which dependent measure.

D) ensure that the participants in the different conditions of the experiment are, on average, equivalent before the experiment begins.

D) ensure that the participants in the different conditions of the experiment are, on average, equivalent before the experiment begins.