Validity Flashcards
validity
“accuracy”
instrument measures what supposed to measure
Types of validity
face validity
content validity
construct validity
criterion validity (concurrent and predictive)
responsiveness
Face validity
simple and subjective determination
sometimes accepted, sometimes not
Content validity
does this “test and/or meaure” easure what is it supposed to measure?
often done by a group of experts
based on subjective opinion
Construct validity
it is the extent to which what was measured was actually measured
the underlying “thing” you want to measure (ex personality-MMPI, intelligence-IQ, knee function-ADL scale of knee outcome survey)
construct is “abstract” or “theoretical” form of validity
Criterion related validity
compare raw measure to relevant criterion variable
basic steps-take measures, measure assoc between the two, generate “r” validity coefficient
This type of validity is often divided into concurrent and predictive subtypes
criterion and responsiveness are “practical” forms of validity
Predictive validity
refers to the degree to which any measure can predict future or independent past events
Concurrent validity
r= assoc between
**picture in slides
Responsiveness
defined as the ability of an instrument to accurately detect change when it has occured
criterion and responsiveness are “practical” forms of validity
Quantifying validity-correlation
correlation- coefficient of determination
normally report “r” for association
common to convert to r2 for validity
it is equivalent to r2 for association
quantifying validity- comparing means
effect size
between groups-construct validity
change over time- responsiveness
ES= (M1 -M2)/ common SD
specific type of signal to noise ratio
large effect= .8
mod effect= .5
small effect= .2
Quantifying validity- factor analysis
quantitative/qualitative process
select factors that explain more variance
