Assumptions of classical test theory

Assumptions of Classical Test Theory The expected value of measurement error within a person is zero. The expected value of measurement error across persons in the population is zero. ... The variance of observed scores across persons is equal to the sum of the variances of true score and measurement error.

1. What parameters are considered under classical test theory?
2. What is classical test theory?
3. Why is the true score in the classical test theory model hypothetical?
4. Who developed classical test theory?

What parameters are considered under classical test theory?

Because random error is always present to at least a minimum extent, the basic formulation in classical test theory is that the observed score is equal to the true score that would be obtained if there were no measurement error plus a random error component, or X = t + e, where X is the observed score, t is the true ...

What is classical test theory?

Classical test theory, also known as true score theory, assumes that each person has a true score, T, that would be obtained if there were no errors in measurement. A person's true score is defined as the expected score over an infinite number of independent administrations of the scale.

Why is the true score in the classical test theory model hypothetical?

The true score of a person can be found by taking the mean score that the person would get on the same test if they had an infinite number of testing sessions. Because it is not possible to obtain an infinite number of test scores, T is a hypothetical, yet central, aspect of CTTs.

Who developed classical test theory?

Charles Spearman was one of the founders of this classical test theory, having an understanding that there were generally always going to be errors in test measurements, that these errors are random variables, and finally, that they could be correlated and indexed.