Hey guys! This is a detailed summary for psychometrics! It covers ALL of the needed literature for the course (Furr, R. M. (2021). Psychometrics: an introduction, Chapters 4 to 11) I got a grade 9.3 :)
UNIDIMENSIONAL TESTS
the testincludes items thatreflect
When
only a
single attribute of a
person
->
the
responses to the testitems are driven
only by thatone attribute)
test
eg. abt.geometry which
requires true
and ONLY tests
knowledge of geometry
geometry (ne
angebra or stn.)
MULTIDIMENSIONAL TESTS W/
CORRELATED DIMENSIONS
ana tests w/ higher order factors
when testitems reflect more than
one
psychological attribute +
the dimensions correlated
if are
->
only a
single score is computed eg. intelligence tests w/ questions abt
diff facets of intelligence (logic
thinking general knowledge...)
when dimensions are carrelated:person
wI
high score in edimension is
likely
to score
high on other dimension
typically
->
produce more scores,
each subset has its own score
-> when correlated: dimension are
scared to produce a total score by
subsets
combining
eg. some personality tests which testfive relatively independent
personcuity attributes
->
test receives five scores which are all treated as if they
were
unidimensional, no total testscore is computed
FACTOR ARALYSIS
this statistical procedure
evaluates the test dimension -
ality
there are two
types:
EXPLORATORY FACTOR ANALYSIS GFA
compute correlations among items and
identify how many dimensions
there really are:
in the
hypothetical correlation matrix
we look for items thatare strongly
correlated w/ each other not
but
other items
=psychological dimension/factor
tallative, assertive, outgoing
-
->
imaginative, creative, intellectual
, EFA STEPS:
1. EXTRACTION METHOD
CHOOSE
which technique? PRINCIPAL AXIS FACTORING (PAF) recommended*
2.IDEUTFY #OF FACTORS +
EXTRACTION
EIGENVALUES
-to
identify # of factors look at
each value represents the potential #of
dimensions reflected among test items
OPTON ONE:
-
than 1.0 then reflects
when itis
greater the item a dimension
eg. if two are 31 then the items reflect I dimensions
OPMON TO:
-
examine relative
the sizes
of the
figenvalues
the 2 and 3
biggestrel, diff. is btwn value
we find the point at which subsequent
differences are relative small (So point3)
and we conclude the test has that
point- 1 dimensions (So 3-1 2)=
we can also plot these values in a SCREf PLOT
wherever the
"leveling off-point"is, then-1
3 1 2D
-
=
D
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 mihaelamasic. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.48. You're not tied to anything after your purchase.
