Chapter 6 Flashcards
Norm-referenced Reliability and Validity
Reliability
the consistency of measurements
Validity
the degree of truthfulness of a test score
Validity is dependent on characteristics:
- reliability
- relevance
Relevance
the degree to which the test pertains to its objectives
Objectivity
is a special type of reliability
Ex: objective test - multipul choice test, or subjective test - essay or writting test
Observed score
your grade on the test
True score
what you actually know
Error score
difference between observed and true score
Observed score
True score + Error score
True score is theoreticly exist but is imposible to measure
true
Reliability coefficient = rxx
range from 0 to 1
- interclass reliability coefficient
- intraclass reliability coefficient
The desireble level of reliability is 0.8 or higher
True
Longer tests are more reliable than shorter tests
True
Index of reliability
theoretical correlation between observed and true scores
Standard Error of Measurement (SEM)
degree to which an observed score fluctuates due to measurement error
Interclass reliability coefficient
based on the PMM correlation coefficient
- test-retest reliability
- equivalence reliability
- split-halves reliability
Test-retest reliability
same test two different times
- scores are corralated using the PMM correlation coefficient
Equivalence reliability
two parallel or equivalent forms of exame are given to students
Ex: if the techer wants to reduce the chetting on the exam, he can give two different test but witb the same idea
Split-halves reliability
splitting the test into parts
allows us to evalute reliability by using ONLY ONE TEST
The Spearman-Brown Prophecy formula is used for this type of
Intraclass reliability coefficient = Kuder-Richardson formula
based on ANOVA
used when we have more than two trials
k
numbers of trials
Types of validity
- content-related
- criterion-related
- construct-related
Content-related validity
known as logical validity
Ex: content experts, expert judges, or textbook writers
criterion-related
Criterion-related validity
based on the relationship between the criterion and other measures
also known as a correlation validity
Types:
- concurrent validity
- predictive validity
