Chapter 4 & 8*

Question 1

What are the two basic research designs?

Answer 1

non-experimental and experimental

Question 2

Non-experimental design

Answer 2

relationships are studied by measuring or observing the variables of interest

Question 3

Experimental design

Answer 3

involves direct manipulation of one variable, control of several other variables (those not of interest), then measurement of an outcome variable

Question 4

Prediction

Answer 4

statement of the hypothesis that has been translated into the specific operationalizations of the study

Question 5

Correlational studies

Answer 5

dominant type of non-experimental design; measure two variables in a group of people and determine if there is a relationship between the variables; used when one or more of the variables cannot be manipulated

Question 6

Correlation coefficient (r)

Answer 6

a.k.a. Pearson product moment correlation; a statistic that indexes the linear relationship between two variables or expresses the strength of a relationship; ranges from -1 to 1

Question 7

Correlation matrix

Answer 7

symmetrical table showing correlation coefficients between variables; used when there are many variables

Question 8

What is the limit of a correlational design?

Answer 8

We can’t conclude causation

Question 9

Internal validity`

Answer 9

ability to infer that independent variable causes changes in the dependent variable with alternative explanations being implausible

Question 10

Two aspects of experimental design that allow causality

Answer 10

experimental control and random assignment

Question 11

Independent variable

Answer 11

manipulated by the researcher; has multiple levels/conditions (usually control and experimental conditions)

Question 12

Dependent variable

Answer 12

measured by the researcher; expected to be affected by the independent variable

Question 13

What are the types of dependent variables?

Answer 13

self-report, physiological, and behavioral

Question 14

Confounds or confounding variables

Answer 14

variable that is intertwined with and co-varies or correlates along with a variable of interest and can explain part or all of the result

Question 15

What are the four most common relationships found in research?

Answer 15

(1) positive linear relationship (2) negative linear relationship (3) curvilinear or inverted U relationship (4) no relationship

Question 16

Mediated relationship

Answer 16

describes how the relationship between two variables can be explained via a third variable

Question 17

Mediating variable or mediator

Answer 17

a psychological (or physiological) process that occurs between an event and a behavioral response that helps to explain the relationship between two other variables

Question 18

Construct

Answer 18

abstract variable, idea, or phenomenon

Question 19

Random variability or error variability

Answer 19

a phenomenon that we can’t predict or explain, or that result from variables not of interest to us

Question 20

Third variable problem

Answer 20

the possibility that a third, unmeasured variable (not intertwined) impacts both variables of interest

Question 21

Experimental control

Answer 21

the only difference between conditions is the independent variable of interest

Question 22

Random assignment

Answer 22

using chance to determine which participants end up in which conditions to control for the effects of extraneous variables not of interest

Question 23

Field experiment

Answer 23

independent variable is manipulated in a natural setting out in the real world

Question 24

What are two broad classes of experimental design?

Answer 24

between-subjects design (or independent groups design) and within-subjects design (or repeated measures design)

Question 25

What are the three steps involved in any between-subjects experiment?

Answer 25

(1) obtaining two approx. equivalent groups of participants (2) introducing different levels of the independent variable to them (3) measuring the dependent variable

Question 26

Selection differences

Answer 26

differences in the type of participants who make up each group in a between-subjects design

Question 27

Matched pairs design or yoked design

Answer 27

Groups are made equivalent by first selecting pairs of participants who score the same on some variable of interest then randomly assigning one to the experimental group and the other to the control group

Question 28

Solomon four-group design

Answer 28

the same experiment is conducted with and without the pretest then the researcher can examine whether is an interaction between the independent variable and the pretest variable (treated as another IV); used when there is concern for demand characteristics

Question 29

Pretest-posttest design

Answer 29

the dependent variable is measured both before (pretest) and after (posttest) manipulation of the independent variable

Question 30

Posttest-only design

Answer 30

the dependent variable is measured only once after manipulation of the independent variable

Question 31

What are the three main reasons why a researcher may add a pretest?

Answer 31

(1) to counter problems associated with a small sample size (2) to select appropriate participants (3) when participants might drop out of the study

Question 32

What is the advantage of a pretest?

Answer 32

it enables the researcher to assess whether groups were already roughly equivalent on some critical variable before the manipulation began

Question 33

Selective attrition

Answer 33

a threat to internal validity when participant dropout results in a difference between conditions on some participant characteristic, causing a confound

Question 34

What is the disadvantage of a pretest?

Answer 34

it can sensitize participants to what you are studying, enabling them to figure out your hypothesis

Question 35

Within-subjects or repeated measures design

Answer 35

all participants experience all conditions and participants are measured on the dependent variable after being in each condition

Question 36

What are the advantages of a within-subjects design?

Answer 36

fewer research participants are needed, it is extremely sensitive and able to detect differences between conditions

Question 37

Order effect

Answer 37

the effect that the order of conditions has on the dependent variable in a within-subjects design

Question 38

What are the three types of order effects?

Answer 38

practice effect, fatigue effect, and contrast effect

Question 39

Practice effect

Answer 39

when performance improves because of repeated practice with a task

Question 40

Fatigue effect

Answer 40

when participants perform worse over the course of a study because of diminished effort or fewer resources due to the passage of time

Question 41

Contrast effect

Answer 41

when participants’ responses in a later condition are affected by a particular experience they had in an earlier condition

Question 42

What are the two ways to deal with order effects in within-subject designs?

Answer 42

(1) using counterbalancing techniques (2) ensuring that the time between conditions is long enough to minimize the influence of the first condition on the second

Question 43

Counterbalancing

Answer 43

a method of controlling for order effects in a within-subjects design by either including all possible orders of presentation for conditions or randomly determining the order for each participant; order is influencing both conditions equally

Question 44

Latin square design (Partial Counterbalancing)

Answer 44

uses a limited set of all possible orders carefully constructed to (1) each condition appears first, second, third, and so on (2) and that each condition appears directly before and after each other condition exactly once