Chapter 3

Question 1

what does choosing of a measure imply in terms of construct?

Answer 1

implies that you endure view/theory associated with that specific measurement

Question 2

what is a formal definition of a construct

Answer 2

what your construct corresponds to

Question 3

what is an operational definition of a construct

Answer 3

how to measure various elements of your formal definition (how to measure your construct)

Question 4

what is a theoretical model?

Answer 4

refers to how a construct is formally defined and operationalized

Question 5

what is a measurement model?

Answer 5

examines how responses from individual questions are interrelated

the extent to which the interrelationship among individual questions implied by your theoretical model can be found in actual responses to questions

Question 6

how is a measurement model different from operationalizing a construct?

Answer 6

operationalizing = involves how a construct is turned into questions/measures

measurement model = involves how numerical answers to questions are scored, and aggregated

Question 7

what are indicators?

Answer 7

indicate the presence of something (construct)

Question 8

what does Plato’s cave allegory describe

Answer 8

describes distinction between constructs/measures/indicators

Question 9

what are the three main points of Plato’s allegory of the cave

Answer 9

we cannot see anything directly (we cannot see things directly, but can make inferences based on indicators)

it is very easy to get things wrong (shadows in allegory are imprecise)

what we observe, even if imprecise, is caused by something real (everything we know is inferred through what we observe)

Question 10

what is the classical test theory?

Answer 10

1st formal theory of how tests work by Robert Novick (1966) that formalizes Plato’s allegory

states that a persons true score is different from observed score

difference due to error

Question 11

what equation represents classical test theory?

Answer 11

T = X + C
or
X = T + E
where x = observed score, t = true score, and e = error

Question 12

what are the difficulties associated with classical test theory?

Answer 12

if we cannot know what the true score is, then it is not possible to calculate the error

if we don’t know how much error there is in the observed score, we cannot calculate the true score

therefore, you have 1 equation with 2 unknowns

Question 13

how can you approximate true score with classical test theory

Answer 13

if we assume that errors are randomly distributed, then through repeated measure, you can get close to approximating what the true score is

Question 14

who came up with item response theory

Answer 14

Frederic Lord, Georg Rasch, and Paul Lazorsfield

Question 15

what is item response theory

Answer 15

explains relationship between an unobservable characteristic/attribute (ex. level of depression) and observational manifestations (ex. responses to test questions)

allows you to estimate how the probability of choosing one of many response options to a question changes with increases in the amount of characteristic/attribute/condition

essentially models the relationship between an individual item and an unobservable characteristic

Question 16

what are option characteristic curves on item response theory graphs?

Answer 16

allow you to make good guesses about level of condition/ability/characteristic based on response to a single question

Question 17

how effective are option characteristic curves on multiple choice questions vs. tests that measure different levels of a characteristic/symptom/ability

Answer 17

multiple choice (only one correct answer out of multiple) = not effective/interesting

tests that measure different levels/tests where all options of question should be modelled/are of interest = ideal criteria

Question 18

what is structural equation modelling?

Answer 18

statistical method used to examine how responses to items are interrelated

allows researchers to convert theory about how individuals questions on a test are interrelated into a set of mathematical equations that describe this

is an example of model testing

Question 19

what are structure equations in structural equation modelling?

Answer 19

used to mathematically describe the relationship between construct and indicators

Question 20

what is model testing

Answer 20

model = testing
model testing = testing a theory
theory = model about what world is like/how things work

Question 21

what is main goal of structural equation modelling?

Answer 21

to turn theoretical statements into a set of mathematical equations with (w actual data) help you understand if theoretical claim is justifiable

Question 22

how can you tell what structural equation model is the best?

Answer 22

model that best captures observed relationships and is closest to nature of construct/study

Question 23

what do scientific models represent?

Answer 23

relationships between scores, theoretical models, observed scores, and error

Question 24

what is unidimensional model

Answer 24

every individual question/indicator can be viewed as measuring sample, single construct

every item/question contributes equally to measuring construct

every error that is introduced through every item score is about the same

relationship among questions that person answers on a test is explained by a single, unobservable entity (construct)

Question 25

what is non-unidimensional model

Answer 25

states that relationship among questions that a person answers on a test is best explained by various separate and unobservable entities which are both understood at part of the overall single overall unobservable construct

Question 26

what does modelling data involve?

Answer 26

involves imposing some structure/idea on the data and examining if that model/imposed structure makes sense

Question 27

what is Ockham’s razor

Answer 27

describes idea that simpler explanations are generally better than more complex ones

if 2 models fit the data equally well, the data is not sufficient to inform which model is best - therefore Ockham’s razor principle should be implemented

Question 28

what is “fit”

Answer 28

how will a model fits the data

Question 29

what are the benefits of simplicity?

Answer 29

simpler is easier to understand/explain things

simpler is better when it comes to measuring constructs and predicting outcomes