Reliability Flashcards
(17 cards)
What is reliability coefficient
It indicates the ratio between true score and the total variance
It indicates the consistency of the test
.70 - .80 is good enough for school research, .95 is recommended in clinical setting. (be careful though, .95 may also indicate the redundancy of the items)
Classical Test Theory
The observed score consists of true score and the error.
Formula of CTT
Observed score= True score + Error
True Variance
Variance from true differences
Error Variance
Variance from irrelevant random sources
What is a variance?
The spread between numbers in a data set; how far is the data set from the mean.
Basic Sampling Theory
The distribution of the random errors is in bell shaped.
In basic sampling theory, center of distribution is the ____
True score
In basic sampling theory, what are the dispersion around the mean is?
Distribution of the sampling errors
What is Reliability
Proprotion of total variance attributed to true variance. Score is still stable even if administered multiple times.
Error variance may ____ or ____ a test score which the reliability of the test can be affected
Increase;decrease
Measurement Error
All of the factors associated in measuring a variable other than the variable being measured.
What are the two types of error?
Random error and Systematic error
Define random error
Source of error caused by unpredictable fluctuations or inconsistiencies in the process.
It doesn’t have any pattern, and it cannot be predicted.
What is systematic error?
Source of error that is constant, and it does not affect the consistency of the scores.
Sources of Error Variance
- Test Construction
- Test Administration
- Scoring and Interpretation
- Methodological Error
