Chapters 8, 9, 10 terms

Question 1

A point estimate

Answer 1

is a summary statistic from a sample that is just one number used as an estimate of the population parameter

Question 2

An interval estimate

Answer 2

is based on a sample statistic and provides a range of plausible values for the population parameter.

Question 3

confidence interval

Answer 3

is an interval estimate based on a stample statistic; it includes the population mean a certain percentage of the time if the same population is sampled from repeatedly.

Question 4

effect size

Answer 4

indicates the size of a difference and is unaffected by sample size.

Question 5

Cohen’s d

Answer 5

is a measure of effect size that expresses the difference between two means in terms of standard deviation.

Question 6

Meta-analysis

Answer 6

is a study that involves the calculation of a mean effect size from the individual effect sizes of more than one study.

Question 7

statistical power

Answer 7

is a measure of the likelihood that we will reject the null hypothesis, given that the null hypothesis is false.

Question 8

t statistic

Answer 8

indicates the distance of a sample mean from a population mean in terms of the estimated standard error.

Question 9

single-sample t test

Answer 9

a hypothesis test in which we compare a sample from which we collect data to a population for which we know the mean but not the standard deviation.

Question 10

degrees of freedom

Answer 10

is the number of scores that are free to vary when we estimate a population parameter from a sample.

Question 11

paired-samples t test

Answer 11

is used to compare two means for a within-group study, a situation in which every partner is in both samples; also called a dependent-samples t test.

Question 12

replication

Answer 12

is the repetition of a study that gives us confidence that a particular observation is true.

Question 13

independent samples t test

Answer 13

is used to compare two means for a between-groups design, a situation in which each participant is assigned to only one condition.

Question 14

pooled variance

Answer 14

is a weighted average fo the two estimates of variance; one from each sample; that are calculated when conducting an independent-samples t test.

Question 15

error bars

Answer 15

are vertical lines added to bars or dots on a graph that represent the variability of those data and give us a sense of how precise an estimate summary statistic is.