Stats Ch. 10

Matched-pairs design, Matched-subjects design, or matched-samples design

A research design in which participants are selected and then matched, experimentally or naturally, based on common characteristics or traits

Related-samples t test

A statistical procedure used to test hypotheses concerning two related samples selected from populations in which the variance in one or both populations is unknown

Within-subjects design

A type of repeated-measures design in which researchers observe the same participants across many treatments but not necessarily before and after a treatment

Matched pairs can be obtained either:

experimentally or through natural occurrence.

The standard error of the mean is used to:

measure the error or unexplained differences in a statistical design.

Two assumptions for a related-samples t test are:

normality and independence within groups.

In a repeated-measures design, the same participants are:

observed in each treatment.

In a related-samples t test, difference scores are:

obtained prior to computing the test statistic.

In a related sample or dependent sample,

participants can be related.

In a matched-pairs design, participants are matched based on:

the characteristics that they share.

Two types of repeated-measures designs are:

the pre-post and within-subjects designs.

Two types of repeated-measures designs are:

the pre-post design and the within-subjects design.

Two types of design for selecting related samples are:

the repeated-measures and matched-pairs designs.

Estimated standard error for difference scores (SmD) is an estimate of:

the standard error or standard distance that the mean difference scores deviate from the mean difference score stated in the null hypothesis.

The mean difference and the estimated standard error for difference scores are:

entered in the formula for a related-samples t test.

The standard deviation of difference scores is used to:

estimate the population standard deviation in the formula for Cohen's d.

Participants can be related in one of two ways:

They are observed in more than one group (a repeated-measures design), or they are matched, experimentally or naturally, based on common characteristics or traits (a matched-pairs design).

The null and alternative hypotheses make statements about:

a population of mean difference scores.

Repeated-measures design

a research design in which the same participants are observed in each treatment.

Difference score

a score or value obtained by subtracting one score from another

When the value stated by a null hypothesis is outside the confidence interval, this indicates:

a significant effect in the population.

Pre-post design

a type of repaired-measures design in which researchers measure a dependent variable for participants before (pre) and after (post) a treatment

Proportion of variance is computed in the same way for:

all t tests.

Estimated standard error for difference scores (SmD)

an estimate of the standard deviation of a sampling distribution of mean difference scores.

For a t test, the term, error, refers to:

any unexplained difference that cannot be attributed to, or caused by, having different treatments.

The degrees of freedom for the related-samples t test equal the number of:

difference scores minus 1.

Computing difference scores prior to computing the test statistic reduces error by:

eliminating one possible source of error, thereby increasing the power of a hypothesis test.