Related Experiment Video
Updated: Oct 2, 2026

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
Published on: July 3, 2020
A nonlinear congeneric model for continuous item responses
1Universidad Rovira i Virgili, Facultad de Psicología, Carretera Valls s/n, 43007 Tarragona, Spain. pjfp@astor.urv.es
Abstract:
This paper presents a unidimensional item response model intended for personality and attitude items that use a continuous response format. The model's starting point is the linear congeneric model for item scores, but it takes into account the bounded nature of the item responses and assumes that their conditional distributions for a fixed trait level are truncated normal. This assumption leads to nonlinear item-trait regressions and considerably modifies some aspects of the linear model. The linear model is considered as an approximation to the modified version, and an interval is defined in which the approximation is satisfactory. Procedures for estimating the item and subject parameters are described. The applicability of the model is illustrated using real data.
Related Concept Videos
Dose Response Curve: Conventional Versus Nonmonotonic
Linear Approximation in Frequency Domain
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear.
Response Surface Methodology
The process of RSM involves several key steps:
Pharmacodynamic Models: Additive and Proportional Drug Effect Model
Feedback control systems
Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity...
Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
