Test Flashcards
What is a reliability
The degree to which there are consistencies of scores achieved on the test
Reliability (rxx) is the proportion of obtained score variance
explained by true score variance
What is a validity
Degree with which test measures what it set out to measure
What is correlation
Degree of relationship between 2 variables. Ranges between -1 and + 1
What does a correlation of +1 means
+1 means that they have a perfect positive correlation so that high scores go for both variables
What does a correlation of -1 mean
-1 is perfect negative correlation such that high scores on one variable go with low scores on the other.
What is the true score model of reliability
If the same test is given to an individual an infinite number of times, the obtained scores will be normally distributed.
In true score model, what is the mean of the distribution
true score
In true score model what is the standard deviation of the distribution
Standard error of measurement
If rxx in true score theory is .8, what is the variance breakdown?
80% variance true score and 20% error score variance
What happens when test is lengthened
Reliability increases
What is the definition of the standard error of measurement
standard deviation of the distribution
What is formula for error variance
1-rxx
What is sources for error variance alternate form (immediate)
Content sampling
What is sources for error variance delayed
Time sampling and content sampling
What is sources for error variance split half
Content sampling
What is sources for error variance kuder richarson-20 and cronbach’s alpha
Content sampling and content heterogenity
What does spearman brown do
Allows us to look a effect of lengthening test
What are the main types of validity
Face validity
Criterion related validity
Content validity
Construct validity
What is face validity
The test appears to be testing what it sets out to
What is content validity
The test covers a representative sample of the domain being measured. COVERS WHOLE AREA
What is criterion related validity
The test scores are compared and correlated with the score on the criterion.
Made up of concurrent validity
Predictive validity
What is construct validity
the test reflects individual differences in a psychological construct E.G. anxiety, illigence
1- convergent . Convergent is high similarity to our test scores and
2- divergent is different
What is difficulty
Proportion of people who selected the correct answer
What is discrimination
6/10-2/10= 4
