Flashcards in Statistics Deck (31):

1

## Mann-Whitney U Test

###
one independent variable - two independent groups

one dependent variable - rank-ordered data

2

## Wilcoxon Matched-Pairs Signed-Ranks Test

###
one independent variable - two correlated groups

one dependent variable - rank-ordered data

3

## Kurskal-Wallis Test

###
one independent variable - two or more independent groups

one dependent variable - rank-ordered data

4

## Mann-Whitney is the nonparametric version of ______

### the t-test for independent samples

5

## Wilcoxon is the nonparametric version of ________

### the t-test for correlated samples

6

## Kurskal-Wallis is the nonparametric version of ________

### the one-way ANOVA

7

## Parametric tests are measured on _____ & _____ scales.

### interval & ratio

8

## Nonparametric tests are measured on _______ & _______ scales.

### nominal & ordinal

9

## Type I error

### investigator rejects a true null hypothesis

10

## Type II error

### investigator fails to reject a false null hypothesis

11

## 3 predictions of the Central Limit Theorem

###
regardless of the shape of the distribution of individual scores in the population, as the sample size increases, the sampling distribution of the mean approaches a normal distribution

mean of the sampling distribution of the mean is equal to the population mean

standard deviation of the sampling distribution of the mean is equal to the population standard deviation divided by the square root of the sample size

12

## formula for standard error of the mean

### SEM = standard deviation / square root of N

13

## variance

### standard deviation squared

14

## percentage of scores within one standard deviation

### 68

15

## percentage of scores within two standard deviations

### 95

16

## percentage of scores within three standard deviations

### 99

17

## t-test

###
used to compare only two means at a time

a study including more than two means (more than two levels of the IV) would require multiple t-tests and would increase experimentwise error rate

18

## ANOVA

###
used to compare two or more means

simultaneously makes all comparisons while holding the probability of making a Type I error at the level of significance set by the experimenter

19

## one-way ANOVA

### used when a study includes one independent variable

20

## factorial ANOVA

### used when a study includes two or more independent variables

21

## Cohen's d

###
measure of the difference between tow groups in terms of standard deviation units

small effect size = 0.2

medium effect size = 0.5

large effect size = 0.8

22

## Eta squared

### indicates the percent of variance in the outcome variable that is accounted for by variance in the treatment

23

## Pearson r

### data on both variables represents a continuous scale (interval or ratio data)

24

## Spearman rho

### both variables are ranks

25

## Point biserial

### one variable is a true dichotomy and the other is continuous

26

## Biserial

### one variable is an artificial dichotomy and the other is continuous

27

## eta

### the variables are both continuous and have a nonlinear relationship

28

## external validity

### the degree to which a study's results can be generalized to other people, settings, conditions, etc.

29

## internal validity

### the degree to which a study allows an investigator to conclude that observed variability in a dependent variable is due to the independent variable rather than to other factors

30

## moderator variables

###
affect the strength or direction of the relationship between independent and dependent variables

if a treatment works better for men than for women, gender is a moderator variable

31