Statistical tests and concepts

Question 1

Alpha

Answer 1

The probability of REJECTING the null hypothesis when it is TRUE
AKA Type I error

Question 2

Beta

Answer 2

The probability of ACCEPTING the null hypothesis when it is TRUE
AKA Type II error

Question 3

Power

Answer 3

The probability of REJECTING the null hypothesis when it is FALSE, or the likelihood of finding differences b/w conditions when the conditions are in fact truly different
Probability = 1-Beta

Question 4

Effect size

Answer 4

A way of expressing the difference b/w conditions in terms of a common metric across measures and across studies
Method = based on obtaining the difference b/w the means of interest on a particular measure and dividing this by the common pooled std deviation

Question 5

Standard deviation

Answer 5

Measure of variation or variability about a mean

Question 6

Effect size

Answer 6

Refers to the magnitude of the difference b/w 2 or more conditions
Expressed in SD units
Reduce variability by controlling features of the experiment - want to
Dependent on the design of the study

Question 7

Holding constant

Answer 7

Increases experimental precision
Conditions held constant incl potential sources of influence on subjs bx
held constant when identical or very close to that across subjs and conditions
Eg race, gender, SES, etc.

Question 8

Controlling sources of variation

Answer 8

Extraneous factors that can contribute to variation
eg time of day, weather, how IV implemented
Let factors vary unsystematically
Disperse factors equally across groups by assigning subjs randomly and by running all subjs in each condition
No systematic bias = well-controlled study

Question 9

Relationships among variables of interest

Answer 9

Correlation
Risk Factor
Cause

Question 10

Correlation

Answer 10

Two or more variables associated

Not cause/effect

Question 11

Risk factor

Answer 11

Character that is an antecedent and increases likelihood of outcome of interest

Question 12

Cause

Answer 12

One variable infl the other directly

Question 13

What factors infl the relationship b/w variables; that is the direction or magnitude of the relation?

Answer 13

Moderator –> A variable that info the relationship of two variables of interest
The relationship b/w A and B changes b/c of some other variable eg gender
WHAT - direction or magnitude

Question 14

How does the phenomenon work; that is, thru what relation or mechanism or thru what process does A lead to B?

Answer 14

Mediator –> The process, mechanism, or means thru which a variable produces a particular outcome
Mechanism elaborates precisely what happens that explains how B results
HOW - mechanism of effect
Deeper understanding

Question 15

Can we control or alter the outcome of interest?

Answer 15

Intervention –>
Is there something we can do to increase or decrease the likelihood of an undesired outcome (prevention)
Or decrease etc something that has already occurred (tx)

Question 16

Theory

Answer 16

refers to a conceptualization of the phenomenon of interest
Incl:
Nature, antecedents, causes, correlates, and consequences of a particular aspect of functioning or characteristic
May specify the relations of various constructs to ea other

Question 17

Different levels of theory

Answer 17

Circumscribed
Conceptual view and model
Broad or narrow

Question 18

Circumscribed theoretical views

Answer 18

characterize contemporary research in an effort to develop specific models or integrated sets of findings and relations among variables
Explain relations b/w characteristics and a d/o and how lead to other dysfxn

Question 19

Conceptual underpinnings

Answer 19

Overall orienting view rather than global concepts
Relate approaches insofar as they often present broad orienting views that encompass constructs of interest
eg CBT for depression

Question 20

Why theory is needed:

Answer 20

1. Bring order to areas where findings are diffuse or multiple
2. Explain the basis of change and unite diverse outcomes
3. Direct our attn to which moderators to study
4. Application and extension of knowledge

Question 21

Overall goal of science

Answer 21

To understand - and this entails connecting empirical relations w statements of mechanisms and processes

Question 22

How do we put theory into practice?

Answer 22

Operational definitions

Question 23

Operational definition

Answer 23

Refers to defining a concept on the basis of the specific operations used in the experiment

Question 24

Limitations of operational definitions

Answer 24

1. Over simplification or focus only on part of the concept
2. Incl irrelevant features
3. Use single measure to define a construct

Question 25

Multiple operationism

Answer 25

Combined measures that attempt to explore a concept w different operations
May allow an investigator to place more confidence in capturing concept of interest
Compensates for inadequacies of using a single measure
Eg To measure cardiovascular functioning: measure blood pressure, stress test, cholesterol, heart rate

Question 26

Notion of latent variable used to…

Answer 26

Reflect the idea of a construct represented by several measures
Bc latent variable = defined by several different measures - it is not confounded by measurement error of a single measure

Question 27

Observed variables

Answer 27

Specific measures

Represent construct of interest

Question 28

In designing a study, what types of variables should I be looking at?

Answer 28

Environmental/situational
Instrumental
Individual differences

Question 29

Environmental/situational variables

Answer 29

Varying what is done to, with, or by the subj
eg:
special intervention
type of tx
task

Question 30

Instructional variables

Answer 30

Refer to a specific type of environmental or situational variable
Variations in what participants are told to do or are led to believe thru written/verbal statements about the experiment and their participation
Eg
Comparing different instructions

Question 31

Subj or indiv differences

Answer 31

Refer to attributes or characteristics of indiv subjects
Not manipulated directly
Varied by selecting subjs w different characteristics, experiences, attributes, or traits
Eg
Age, education, sex, social class, exposure to trauma, scores on personality measures, dx, being twin or only child, etc.
Person w or w/out or w varying degrees of characteristic = compared