Method for assessing the accuracy of test results
A method for developing and validating a quality assessment for a test is provided. A test method is also provided, which assesses the accuracy of a test. The methods include performing a behavioral test on a subject to measure a psychometric quantity, measuring one or more quality indicators, the quality indicators being any variables that are correlated with test accuracy, obtaining an independent measure of test accuracy, and deriving a predictive formula for estimating test accuracy from the quality indicators.
1. A method for developing a predictive formula for calculating a quantitative measure of test accuracy, comprising:
performing a behavioral test on a subject using a test system to measure a psychometric quantity;
measuring the psychometric quantity to provide a test measurement of the psychometric quantity;
measuring one or more quality indicators to provide one or more quality indicator measurements, the quality indicator being any variable that gives an indication of test accuracy;
obtaining an independent measurement of the psychometric quantity for the subject, independent measurement being obtained separately from said behavioral test;
calculating a difference between the test measurement and the independent measurement;
determining a relationship between the quality indicator measurements and the difference between the test measurement and the independent measurement; and
deriving a predictive formula based on the relationship, wherein the predictive formula can be used to calculate a quantitative measure of test accuracy in the behavioral test on future subjects.
2. The method of claim 1 wherein the performing a behavioral test comprises:
providing stimuli to the subject; and
receiving, from the subject, responses to the stimuli.
3. The method of claim 1 wherein the measuring one or more quality indicators comprises measuring quality indicators based upon variables seen when the stimuli is provided or when the responses are received.
4. The method of claim 1 wherein the obtaining an independent measurement comprises performing a method for measuring the psychometric quantity that is regarded as an accurate method for measuring that psychometric quantity.
5. The method of claim 4 wherein the obtaining an independent measurement comprises performing a standardized test method for measuring the psychometric quantity.
6. The method of claim 1 wherein the deriving a predictive formula comprises performing a multiple regression for the quality indicator measurements and the difference between the test measurement and the independent measurement.
7. The method of claim 6 wherein the predictive formula is QA=Q i −Q m =f(QI n ).
8. The method of claim 1 wherein at least one of the quality indicators is a behavior.
9. The method of claim 8 wherein at least one of the quality indicators is a subject behavior.
10. The method of claim 1 wherein the steps of performing a behavioral test on a subject to measure a psychometric quantity is administered automatically and the step of obtaining an independent measurement of the psychometric quantity is administered manually.
11. The method of claim 1 wherein the behavioral test is a hearing test and the psychometric quantity is a frequency threshold.
12. The method of claim 11 wherein the one or more quality indicators include a masker alert rate, time per trial, average number of trials for a threshold, total elapsed time, false alarm rate, average test-retest difference, quality check fail rate, air-bone gap >50 dB and air-bone gap <−10 dB.