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.
Who invented classical test theory?
Classical test theory as we know it today was codified by Novick (1966) and described in classic texts such as Lord & Novick (1968) and Allen & Yen (1979/2002).
Who is known as the father of classical test theory?
Charles Spearman
What is the formula of 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 true score theory?
Classical Test Theory (CTT), sometimes called the true score model, is the mathematics behind creating and answering tests and measurement scales . The goal of CTT is to improve tests, particularly the reliability and validity of tests. ... A test is valid if it measures what it's supposed to.
What is modern test theory?
IRT is a probabilistic (statistical, logistic) model of how examinees respond to any given item(s). Item response theory (IRT) can be contrasted with classical test theory in several ways; often IRT is referred to as “modern” test theory, which contrasts it with “classical” test theory. IRT is NOT psychometrics.
What are the 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. True score is uncorrelated with measurement error in the population of persons .
What are the limitations of classical test theory?
The vast majority of IS studies uses classical test theory (CTT), but this approach suffers from three major theoretical shortcomings: (1) it assumes a linear relationship between the latent variable and observed scores, which rarely represents the empirical reality of behavioral constructs; (2) the true score can ...
What is a test theory?
the body of theory underlying the interpretation and use of test scores . Theoretical frameworks include classical test theory, generalizability theory, and item response theory. ...
What is domain sampling theory?
Domain sampling theory assumes that the items that have been selected for any one test are just a sample of items from an infinite domain of potential items . Domain sampling is the most common CTT used for practical purposes.
What is reliability coefficient?
A reliability coefficient is a measure of the proportion of true variance relative to the total observed score variance resulting from the application of a measurement protocol (such as a test, a scale, an expert rating, etc.) to a population of individuals.
What are two advantages of item response?
Discussion. The two most important advantages provided by an IRT application during the development and analyses of these scales are probably item and ability parameter invariance and test information functions .
What is a true score?
True score, which is the primary element of true score theory, is the individual's score on a measure if there was no error . ... The concept of true score is important to research design as it emphasizes that there is some error involved in any type of measurement (e.g., height, weight, self-esteem, IQ, and heart rate).
When was the true score theory created?
Granted that parallel test forms can be constructed, the true-score theory in Gulliksen ( 1950 , chs.
What are the types of reliability?
- Internal reliability assesses the consistency of results across items within a test.
- External reliability refers to the extent to which a measure varies from one use to another.
What is the difference between classical test theory and item response theory?
The most important difference between CTT and IRT is that in CTT, one uses a common estimate of the measurement precision that is assumed to be equal for all individuals irrespective of their attribute levels. In IRT, however, the measurement precision depends on the latent-attribute value.
