Cognitive Diagnostic Models
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**Introduction**
*"The predominant psychometric paradigm since the 1980s is item response theory, which is also known as latent trait theory. Cognitive diagnostic models are part of a different paradigm known as latent class theory. Instead of assuming that we are measuring a single neatly unidimensional factor, latent class theory instead tries to assign examinees into more qualitative groups by determining whether they categorized along a number of axes.*
*What this means is that the final “score” we hope to obtain on each examinee is not a single number, but a profile of which axes they have and which they do not. The axes could be a number of different psychoeducational constructs, but are often used to represent cognitive skills examinees have learned. Because we are trying to diagnose strengths vs. weaknesses, we call it a cognitive diagnostic model."* [(Thompson, 2017)][1]
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**Overview & Applications**
- A variety of cognitive diagnotic models (CDMs) to help with the diagnotic assessment and evaluation of students:
- [Comparison among cognitive diagnostic models for the TIMSS2007 fourth grade mathematics assessment (Yamaguchi & Okada, 2018)][2]
[1]: http://www.assess.com/what-are-cognitive-diagnostic-models/
[2]: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0188691