Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Natural Selection and Adaptation

Natural Selection and Adaptation

Natural selection, a fundamental concept in evolutionary biology, is the mechanism by which evolution is driven, favoring organisms that are best adapted to their environments. This process enhances their chances of survival and reproduction. Adaptation, a key outcome of this process, involves genetic modifications that optimize an organism's functionality under specific environmental challenges, such as extreme cold or thinner air at high altitudes.
Beyond physical adaptations,...

Introduction to z Scores

Introduction to z Scores

A z score (or standardized value) is measured in units of the standard deviation. It tells you how many standard deviations the value x is above (to the right of) or below (to the left of) the mean, μ. Values of x that are larger than the mean have positive z scores, and values of x that are smaller than the mean have negative z scores. If x equals the mean, then x has a zero z score. It is important to note that the mean of the z scores is zero, and the standard deviation is one.
z scores...

Introduction to z Scores

Introduction to z Scores

A z score (or standardized value) is measured in units of the standard deviation. It indicates how many standard deviations the value x is above (to the right of) or below (to the left of) the mean, μ. Values of x that are larger than the mean have positive z scores, and values of x that are smaller than the mean have negative z scores. If x equals the mean, then x has a zero z score. It is important to note that the mean of the z scores is zero, and the standard deviation is one.
z scores...

z Scores and Area Under the Curve

z Scores and Area Under the Curve

z scores are the standardized values obtained after converting a normal distribution into a standard normal distribution. A z score is measured in units of the standard deviation. The z score tells you how many standard deviations the value x is above (to the right of) or below (to the left of) the mean, μ. Values of x that are larger than the mean have positive z scores, and values of x that are smaller than the mean have negative z scores. If x equals the mean, then x has a z score of...

The Scientific Method

The Scientific Method

The scientific method is a detailed, empirical problem-solving process used by biologists and other scientists. This iterative approach involves formulating a question based on observation, developing a testable potential explanation for the observation (called a hypothesis), making and testing predictions based on the hypothesis, and using the findings to create new hypotheses and predictions.
Generally, predictions are tested using carefully-designed experiments. Based on the outcome of these...

What is Natural Selection?

What is Natural Selection?

Natural selection is an evolutionary process in which individuals with survival-promoting traits reproduce at higher rates. These favorable traits become more common within a population or species. Naturally selected traits initially arise via random genetic mutations. In order for selection to occur, there must be variation within a population, the trait controlling the variation must be heritable, and there must be an evolutionary advantage for variation in the trait.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

An IRtree Model for Aberrant Response and Missing Data.

Multivariate behavioral research·2026

Same author

A Sequential Generalized Nonparametric Classification Method for Small-Scale Cognitive Diagnostic Assessment.

Behavioral sciences (Basel, Switzerland)·2026

Same author

Risk and protective factors for suicidal ideation and suicide attempts among Chinese university students: a systematic review and meta-analysis of longitudinal studies.

BMC public health·2026

Same author

A multi-strategy cognitive diagnosis model based on response times and fixation counts.

Behavior research methods·2026

Same author

Psychometric properties of the short mood and feelings scale among Chinese adolescents using item response theory.

Frontiers in psychiatry·2025

Same author

A new person-fit statistic for the detection of aberrant responses in polytomous cognitive diagnostic models.

Behavior research methods·2025

Same journal

The EM Algorithm and Its Variants in Cognitive Diagnostic Models: Comparing Their Propensity for Boundaries, Extremes, Convergence, and Suboptimal Solutions.

Applied psychological measurement·2026

Same journal

When Perceptions of Social Desirability Differ: Implications for the Multidimensional Nominal Response Model of Faking.

Applied psychological measurement·2026

Same journal

csemGT: An R Package for Estimating Raw-Score Conditional Standard Errors of Measurement in Generalizability Theory.

Applied psychological measurement·2026

Same journal

Confirmatory Factor Analysis with Adaptive Quadrature Estimator Using Four Link Functions.

Applied psychological measurement·2026

Same journal

Automatic Item Generation Measurement Models Respecting the Stochastic Sampling Space for Cross-Classified and Two-Level Sampling of Subjects and Incidentals.

Applied psychological measurement·2026

Same journal

Multistage Testing for Cognitive Diagnosis Based on Skill-Space Partitioning.

Applied psychological measurement·2026

See all related articles

Search research articles

Related Experiment Video

Updated: Jan 31, 2026

Computerized Adaptive Testing System of Functional Assessment of Stroke

Computerized Adaptive Testing System of Functional Assessment of Stroke

Published on: January 7, 2019

Item Selection Methods in Multidimensional Computerized Adaptive Testing With Polytomously Scored Items.

Dongbo Tu¹, Yuting Han^1,2, Yan Cai¹

¹School of Psychology, Jiangxi Normal University, Nanchang, China.

Applied Psychological Measurement

|December 19, 2018

Summary

This summary is machine-generated.

New item selection algorithms for polytomously scored adaptive tests (PMCAT) improve accuracy and reduce item exposure. The modified continuous entropy method (MCEM) is ideal for low dimensions, while MUI and MCEM perform well in high dimensions.

Keywords:

Fisher information Kullback–Leibler information multidimensional computerized adaptive test multidimensional graded response model polytomous items

More Related Videos

Author Spotlight: Validation of SICOLE-R for Assessing Cognitive and Reading Skills in Spanish-Speaking Children and Its Role in Personalized Education

Author Spotlight: Validation of SICOLE-R for Assessing Cognitive and Reading Skills in Spanish-Speaking Children and Its Role in Personalized Education

Published on: August 16, 2024

Use of a Video Scoring Anchor for Rapid Serial Assessment of Social Communication in Toddlers

Use of a Video Scoring Anchor for Rapid Serial Assessment of Social Communication in Toddlers

Published on: March 14, 2018

Related Experiment Videos

Last Updated: Jan 31, 2026

Computerized Adaptive Testing System of Functional Assessment of Stroke

Computerized Adaptive Testing System of Functional Assessment of Stroke

Published on: January 7, 2019

Author Spotlight: Validation of SICOLE-R for Assessing Cognitive and Reading Skills in Spanish-Speaking Children and Its Role in Personalized Education

Author Spotlight: Validation of SICOLE-R for Assessing Cognitive and Reading Skills in Spanish-Speaking Children and Its Role in Personalized Education

Published on: August 16, 2024

Use of a Video Scoring Anchor for Rapid Serial Assessment of Social Communication in Toddlers

Use of a Video Scoring Anchor for Rapid Serial Assessment of Social Communication in Toddlers

Published on: March 14, 2018

Area of Science:

Psychometrics
Educational Measurement
Computerized Adaptive Testing

Background:

Traditional Multidimensional Computerized Adaptive Testing (MCAT) primarily handles dichotomous items.
Polytomous items offer richer data and assess complex skills, necessitating advanced adaptive testing methods.

Purpose of the Study:

To explore and propose item selection algorithms for MCAT with polytomous items (PMCAT).
To evaluate the performance of extended and novel item selection strategies in PMCAT.

Main Methods:

Extension of existing MCAT item selection algorithms to the PMCAT framework.
Development of two new item selection methods for PMCAT.
Conducting two simulation studies to assess algorithm feasibility and performance.

Main Results:

Most extended item selection methods for PMCAT demonstrated feasibility.
Proposed methods, particularly the modified continuous entropy method (MCEM), showed strong performance.
MCEM achieved low item exposure and high accuracy in two-dimensional settings.
Mutual information (MUI) and MCEM maintained high accuracy in high-dimensional settings with decreasing exposure rates as correlation increased.

Conclusions:

The developed algorithms are feasible for PMCAT.
The modified continuous entropy method (MCEM) and mutual information (MUI) are effective strategies for item selection in PMCAT, balancing accuracy and item security.