Chapter 4: Defining And Measuring Variables

Question 1

Variable

Answer 1

Any factor that has 2 or more values

Question 2

Constant

Answer 2

Something that is non-changing

Question 3

Qualitative Variables:

Answer 3

properties that differ in type (Sex, religions, eye colour)

can still be statistically analyzed measuring number of instances in each category

Question 4

Quantitative Variables:

Answer 4

properties that differ in amount (height, weight, distance)

Question 5

Discrete Variables

Answer 5

between 2 adjacent values no intermediate values are possible

Question 6

Continuous Variables

Answer 6

Intermediate values are possible between any 2 adjacent scale values

CONVERTING continuous variables into discrete variables in order to measure findings is very common
(example: intensity of depression, measured on a 5 point scale)

Question 7

Independent Variable

Answer 7

• presumed cause in a cause effect relation

- manipulate or systematically vary in order to see effect on a behaviour or outcome

Question 8

Dependent Variable

Answer 8

presumed effect in a cause effect relation

-behaviour or outcome that researcher measures to determine whether independent variable has produced an effect

Question 9

Situational Variable

Answer 9

A characteristic that differs across environment or stimuli

Question 10

Subject Variable

Answer 10

A personal characteristic that differs across individuals task

Question 11

Can independent variables be used in descriptive research?

Answer 11

Yes, they are not manipulated, but the variable can be discussed and conceptualized, an example of this would be measuring through interviews how religious a subject is

Question 12

Hypothetical Constructs and example!

Answer 12

underlying characteristics or processes that are directly NOT directly observed but instead are inferred from measurable behaviour or outcomes
Example: can’t observe hunger, but can infer it

-must be translated into something measurable by operalizatinoalism

Question 13

Manifest Variables

Answer 13

are variables easy to observe like physical characteristics

Question 14

Operationalization

Answer 14

translate a construct into something that can be measured

need to properly conceptualize and communicate how variable will be manipulated or measured

Question 15

Mediator Variables (why)

Answer 15

Provides a causal link between dependent and independent variable and explains relationship

Question 16

Moderator Variables (when, and whom)

Answer 16

A factor that alters strength or direction of the relationship between the independent and dependent variable

An Independent Variable may have different effect on dependent variable depending on age, gender, self esteem

Question 17

Conceptual definitions:

Answer 17

Planning errors, execution errors: defining key concepts

Question 18

Measurement

Answer 18

Systematically assigning values(#’s, labels) to represent attributes of organism, objects or event.s

Question 19

Scales of Measurement 4 MEASUREMENTS

Answer 19

-Impacts how data can be represented, analyses and interpretted

Nominal
Ordinal
Interval
Ratio -most precise

Question 20

Nominal Scale

Answer 20

• Meant for organizing data
• scale values represent qualitative differences
• Group variables into categories
• Differ in type NOT degree
• numbers can be assigned to represent category. but not numerical

Question 21

Ordinal Scale

Answer 21

• different scale values represent relative difference in the amount of some attribute
• rank order
• can be represented by numbers or category
• tells what level an item belongs to, but not difference between rank orders
• doesn’t say how distant an A is from a B just provides info of greater, worse, more than, less than

Question 22

Interval Scale

Answer 22

When equal difference between values on the scale reflect equal differences in the attributes being measured

• numbers reflect the actual amounts
• 0 point is arbitrary
• Difference between 4 and 8 degrees same as 10 and 14
• often record psychological measures on this scale, but sometimes if can’t draw equal intervals it is an ordinal scale

Question 23

Ratio scale

Answer 23

when equal values on the scale reflect equal difference in the amount of attribute being measured

• like Interval scales, but has a true 0 point
• Provides most info about an attribute being assessed
• A score of 0 means absence of attribute
• time length, annual income is measurable

Question 24

Accuracy of Measurement

Answer 24

degree to which the measure yields results that agree with a known standard.
If measurement tool to measure weight isn’t collobarted properly then weight won’t be accurate

Question 25

Measurement error

Answer 25

Things we don’t want to measure but do, due to imperfections of our measurement tool

Question 26

True score

Answer 26

actual degree of characteristic of individual being measured

Question 27

Systematic Error

Answer 27

A consistent degree of error that is inaccurate with each measurement

Question 28

Reliability

Answer 28

Consistency of measurement tool

Question 29

Random measurement error

Answer 29

random fluctuations during the measurement and cause obtained scores to deviate from try score

Question 30

Test-Retest Reliability

Answer 30

administering the same measure to the same participants on 2 or more occasions under equivalent test conditions

Question 31

Alternative forms

Answer 31

A method where 2 versions of the same test are administered to the same participants and different times, to avoid bias effect to reassure reliability of results

Question 32

Split-Half Reliability

what is the average of all split half combinations

Answer 32

Items that compose a test that are divided into 2 subsets; and correlation between 2 subsets is determined
-assesses internal consistency

-split-half combinations average: Cronbachs Alpha

Question 33

Interobserver reliability

Answer 33

degree to which independent observers show agreement in their observations

Question 34

Validity of measure

Answer 34

Alignment between construct and measurement tool we employed to gain insight into the construct

Question 35

Face Validity:

Answer 35

The degree to which items talked about in the measure seem reasonable to participants, and makes sense based on studies purpose

Question 36

Content Validity:

Answer 36

degree to which the items on a measure adequately cover all domain of interest (range or set of items)

Question 37

Criterion Validity:

and what are the 2 different types

Answer 37

• Addresses relation between scores on a measure and an outcome
• Predictive validity: scores on a job test predict increase job performance in the future
• Concurrent Validity: Give GRE test to current college students to see if current results are a factor of success

Question 38

Construct validity:

Answer 38

Measure that truly assesses the construct that it is claimed to assess

Question 39

Convergent Validity:

Answer 39

scores on a measure should highly correlate with scores on a measure of the same construct

-ex/ scores on new depression scale should correlate high with scores on previously established depression scale

Question 40

Discriminant Validity:

Answer 40

Scores on a measure should not correlate strongly with scores on a measure of other constructs