Research Methods and Stats

Question 1

A ___ variable affects the direction or strength of the relationship between IV and DV; whereas a _____ variable EXPLAINS the relationship between the IV and DV

Answer 1

A moderator variable affects the direction or strength of the relationship between IV and DV; whereas a mediator variable EXPLAINS the relationship between the IV and DV

Question 2

A frequency polygon is helpful for what type of data?

Answer 2

Interval (difference between categories or level is equal) or Ratio (difference between categories is equal AND there is an absolute 0)

Freq. polygon is interpreted as normal or non-normal

Question 3

Normal distribution: percentile of scores with 1SD, 2SD: 3SD

Answer 3

68, 95, 99

Question 4

Leptokurtic distribution

Platykurtic distribution

Answer 4

Leptokurtic distribution: more scores piled up in middle so sharp peak and flatter tails
Platykurtic distribution: flatter in middle and thicker tails

Question 5

Differential selection

Answer 5

differential assignment of subj to treatment groups where the groups differ at the beginning of the study due to the way they were assigned to groups (i.e., soccer players already had better eye movement ability at the beginning); a threat to internal validity; addressed with random assignment

Question 6

History, maturation, differential selection, statistical regression to the mean are all examples of what

Answer 6

threats to internal validity

Question 7

Solomon 4 group design

Answer 7

used to identify the effects of pretesting on a study’s internal and external validity; the study includes 4 groups (2 groups take pretest, 2 groups take posttest)

Question 8

The CPT-2 changing to the CPT-3 for patients in the same research sample is an example of

Answer 8

Instrumentation

Question 9

Experimenter expectancy and demand characteristics are both examples of

Answer 9

Reactivity; threatens external validity

Question 10

Whta do grounded theory, thematic analysis, and phenomenology have in common?

Answer 10

They all involve interviews.
Grounded theory - come up with a theory based on participant views
Phenomenology - gain an in-depth look at the lived experience of participants
thematic analysis - look for patterns within interviews

Question 11

ethnography

Answer 11

study and observe and participate in culture and groups in their setting

Question 12

Is triangulation qualitative or quantitative

Answer 12

Both - using multiple types of sources of evidence to understand a topic

Question 13

When does the treatment phase occur in single subject design

Answer 13

The treatment phase does not usually begin until a stable pattern of performance on the dependent variable is established during the baseline phase

Question 14

The primary characteristic that distinguishes true experimental research from quasi-experimental research is that, when conducting a true experimental research study, the researcher is able to:

Answer 14

randomly assign subjects to different treatment groups.

Question 15

homoscedasticity

Answer 15

homoscedasticity – assumption of regression that the variability of criterion scores is similar for all predictor scores

Question 16

If one variable is continuous and the other is a dichotomous variable, what type of regression do you use?

Answer 16

point biserial correlation coefficient

*biserial correlation coefficient is used when one variable is continuous and the other is an artificial dichotomy. An artificial dichotomy occurs when a continuous variable is dichotomized. Final exam scores represent an artificial dichotomy when a cutoff score is used to divide the scores into two categories – pass and fail.

Question 17

Discriminant function analysis is used when two or more predictors will be used to examine their effect on what type of outcome?

Answer 17

Nominal variable (group status)

Example: how do symptoms of depression, anxiety, and alcohol use freq predict smoking versus non smoking status

Question 18

____ is the alternative to the Pearson r for calculating the correlation between two continuous variables when the variables have a nonlinear relationship.

Answer 18

Eta

Question 19

If you reject a true null hypothesis or retain a false null hypothesis, you are making

Answer 19

An incorrect decision (Type I error (alpha) or type II error (beta))

Question 20

the ability to reject a false null hypothesis

Answer 20

statistical power; the larger the alpha, the bigger the sample, and the larger the effect size, the greater the power

Question 21

The central limit theorem predicts that the sampling distribution of means increasingly approaches normal as the sample size

Answer 21

sample size increases regardless of the shape of the population distribution.

Question 22

Formula for SEM

Answer 22

population SD/sq. root of sample size

Question 23

A non-parametric test deals with non-normal data but also

Answer 23

nominal and ordinal data and include the chi-square test

Question 24

Biggest diffence between t-test and one-way ANOVA?

Answer 24

t-test you can only have two groups (CBT vs. ACT) whereas one-way ANOVA you can have 2+ (CBT vs. ACT vs. Client Centered)

Question 25

F-ratio; what is it and when do you know that the IV has had an effect on the DV

Answer 25

F = MSB (mean square between)/MSW (mean square within)

MSB = variability due to tx + error
MSW = variability due to error 

F > 1 = effect of IV

Question 26

Experimentwise error rate ____ the more statistical tests you run

Answer 26

Increases

Question 27

Effect size is a practical significant test; Cohen’s d is often used and is calculated by

Answer 27

(Mean Group 1 - Mean Group 2)/SD of both groups combined

Question 28

What is the difference between a one-way, two-way, and three-way ANOVA

Answer 28

The number of IVs
one way = Effect of SES on BMI
two-way = Effect of SES and Age on BMI
three-way = Effect of Age, SES, and diet on BMI

Question 29

Median should be used instead of mean for

Answer 29

skewed data

Question 30

Can you use a chi-sqare for repeated observations

Answer 30

No

Question 31

Idiographic research design

Answer 31

single subject

Question 32

A researcher would use the split-plot ANOVA to analyze the data she collected in her research study when:

Answer 32

C. her study included one between-subjects independent variable and one within-subjects independent variable.

Question 33

canonical correlation

Answer 33

appropriate multivariate technique when two or more predictors will be used to estimate status on two or more criteria.

Question 34

The central limit theorem predicts that, regardless of the shape of the population distribution of scores, a sampling distribution of means increasingly approaches the shape of:

Answer 34

a normal distribution as the sample size increases.