In psychometrics

Psychometrics

Psychometrics is the field of study concerned with the theory and technique of psychological measurement, which includes the measurement of knowledge, abilities, attitudes, personality traits, and educational measurement...

, item response theory (IRT) also known as latent trait theory, strong true score theory, or modern mental test theory, is a paradigm for the design, analysis, and scoring of tests, questionnaire

Questionnaire

A questionnaire is a research instrument consisting of a series of questions and other prompts for the purpose of gathering information from respondents. Although they are often designed for statistical analysis of the responses, this is not always the case...

s, and similar instruments measuring

Measurement

Measurement is the process or the result of determining the ratio of a physical quantity, such as a length, time, temperature etc., to a unit of measurement, such as the metre, second or degree Celsius...

 abilities, attitudes, or other variables. It is based on the application of related mathematical model

Mathematical model

A mathematical model is a description of a system using mathematical concepts and language. The process of developing a mathematical model is termed mathematical modeling. Mathematical models are used not only in the natural sciences and engineering disciplines A mathematical model is a...

s to testing data

Data

The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...

. Because it is generally regarded as superior to classical test theory

Classical test theory

Classical test theory is a body of related psychometric theory that predict outcomes of psychological testing such as the difficulty of items or the ability of test-takers. Generally speaking, the aim of classical test theory is to understand and improve the reliability of psychological...

, it is the preferred method for the development of high-stakes tests

High-stakes testing

A high-stakes test is a test with important consequences for the test taker. Passing has important benefits, such as a high school diploma, a scholarship, or a license to practice a profession...

 such as the Graduate Record Examination

Graduate Record Examination

The Graduate Record Examinations is a standardized test that is an admissions requirement for many graduate schools in the United States, in other English-speaking countries and for English-taught graduate and business programs world-wide...

 (GRE) and Graduate Management Admission Test

Graduate Management Admission Test

The Graduate Management Admission Test is a computer-adaptive standardized test in mathematics and the English language for measuring aptitude to succeed academically in graduate business studies. Business schools use the test as a criterion for admission into graduate business administration...

 (GMAT).

The name item response theory is due to the focus of the theory on the item, as opposed to the test-level focus of classical test theory, by modeling the response of an examinee of given ability to each item in the test.