Summary
2.5 Chapter 4 Summary
- Course
- Institution
- Book
Summary of Chapter 4
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
More summaries for
-
Psychometrics Summary - Everything you need to know
-
Grade: 9.6!! 2.5 Psychometrics: DETAILED notes Lectures and Readings FSWP2-052-A
-
Summary of Book Chapters for Course 2.5 Psychometrics: An introduction
Seller
Follow
lablyth
Reviews received
Content preview
Chapter 4Test Dimensionality and Factor Analysis
Test dimensionality crucial in test development, evaluation, use
3 fundamental psychometric questions about test dimensionality:
3 main types of test:
1. Unidimensional tests
2. Multidimensional tests with correlated dimensions
3. Multidimensional tests with uncorrelated dimensions
- Must know what test type is used as have important psychometric differences
Test dimensionality
- When measuring a physical or psychological attribute, intention is to measure
a single attribute of the object/person
- Composite score should also ideally only reflect one dimension
Q1. Tests can measure on single or multiple dimensions
- Each test dimension likely to be scored separately
Q2. Some test dimensions are related to each other, whilst others are independent
- Nature of associations can be important for meaningfulness of total score of a
test
Q3. If we score and interpret dimension of a test, must understand the score’s
psychological meaning
1. Unidimensional tests- tests including items that only reflect a single
attribute, so responses to items are only driven by one attribute
, o Test questions usually have conceptual homogeneity (CH)-
responses to each item are a function of the same psychological
attribute
o Single score is computed reflecting single psych. attribute measured
All items combined to create composite (total) score
2. Multidimensional Tests with Correlated Dimensions- multiple
dimensions that are associated with each other
Eg. Stanford-Binet test
o Groups of questions assessing different psych. attributes
Groups= subtests- each reflect different facet
o Responses to question affected by specific or factor attribute
Higher-order factor- general psychological attribute
potentially affecting each specific attribute
o Can produce variety of scores
Typically, each subtest has own subtest score
Each subtest is unidimensional and questions in it have
CH
o Have score for each subtest, which is evaluated regarding its’
psychometric quality
Could have some subtests with good quality and others with bad
o Often scored to produce total score, combined across many subtests
3. Multidimensional Test with Uncorrelated Dimensions- multiple
dimensions that are not associated with each other
Eg. personality tests (Five Factor Inventory)
o No total test score computed (unlike w/ correlated dimensions)
o Score obtained for each dimension
o Each dimension score evaluate in terms of psychometric quality
Psychological Meaning of Test Dimensions
To interpret test dimensions accurately, must research the psychological attribute
represented by each test
Factor Analysis
Most common method of examination
Allows addressing of Q1-Q3, allowing insight to potential scores, evaluation, and use
of the tests
2 main types:
1. Exploratory factor analysis (EFA)
o More common type
o Easily to conduct with basic stat. software
o Used in early stages of psychometric analysis/development
2. Confirmatory factor analysis (CFA)
EFA Overview
- Better to base arguments on empirical data
o Subjects answer on Likert scale
o Enter data into statistical software compute program
o Compute correlation amongst the items
- Set=highly correlated items, shows psychological factor
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller lablyth. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.21. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
72042 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now