Summary
Psychometry Summary
- Course
- Institution
All weeks of literature summarized, except week 3.
[Show more]
Seller
Follow
MayrimK
Reviews received
Content preview
, Week 1 | measurement, scaling and normsLiterature
Furr chapters 1 – 3
Definition of psychometrics: The science concerned with evaluating the attributes of
psychological tests.
Difference experimental and differential psychology:
o Experimental psychology focuses on ‘the average person’, individual differences =
noise/error.
o Differential psychology mostly concerns itself with measuring the differences
between people, comparing measurements.
Measurement: the assignment of numerals to objects or events according to rules
Scaling: concerns the way numerical values are assigned to psychological attributes.
Sum of squares: ∑ ¿¿
Variance: s =∑ ¿ ¿ ¿ Square root of variance gives standard deviation.
2
Covariance: represents the degree of association between the variability in two distributions
of scores.
o c xy =
∑ ( x−x ) ( y− y )
N −1
Product-moment correlation: represents the association between two variables much more
clearly than covariance
c xy
o r xy =
sx s y
Measurement scales
o Nominal: identity (categories, mutually exclusive and exhaustive)
o Ordinal: plus an order
o Interval: plus quantity (measuring unit)
o Ratio: plus absolute zero
Z-score: number of SD from the mean
o Mean = 0
SD = 1
X−M x
o Zx=
SD x
o Add to paper: formula for SD
T-score: easier to understand, friendlier than Z-scores. Only positive outcomes.
o Mean = 50
SD = 10
o T x =10 × Z x +50
Percentile ranks Px : percentage of scores equal or lower than specific test score.
Interindividual differences: comparing different people.
Intraindividual differences: comparing within people.
,
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 MayrimK. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $6.16. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
83637 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now