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knowledge_assessment:q-matrix [2012/07/11 10:02]
jpetrovic [What is a q-matrix?]
knowledge_assessment:q-matrix [2012/07/11 10:15]
jpetrovic [How does a q-matrix look like?]
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 Q-matrix is a M//x//N matrix, where M equals the number of questions in an assessment, and N equals the total number of concepts required for understanding all questions. The matrix element A[i,j] equals 1 if the i-th concept is required for correctly answering j-th question and 0 if the i-th concept is NOT required for correctly answering j-th question. Alternatively,​ matrix values can be not just {0,1}, but real numbers from the interval [0,1], describing the probability that a student who knows i-th concept will correctly answer j-th question. Q-matrix is a M//x//N matrix, where M equals the number of questions in an assessment, and N equals the total number of concepts required for understanding all questions. The matrix element A[i,j] equals 1 if the i-th concept is required for correctly answering j-th question and 0 if the i-th concept is NOT required for correctly answering j-th question. Alternatively,​ matrix values can be not just {0,1}, but real numbers from the interval [0,1], describing the probability that a student who knows i-th concept will correctly answer j-th question.
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 +An example of a q-matrix is shown in the following image.
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 +{{:​knowledge_assessment:​qm.jpg}}
  
 ==== What can I do with a q-matrix? ==== ==== What can I do with a q-matrix? ====
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    * To build the q-matrix, experts constructed a relationship between test questions and concepts (referred to as attributes) and students taking the test were assigned knowledge states based on their test answers and the constructed q-matrix ((see Ham85 for a discussion of item-response theory))    * To build the q-matrix, experts constructed a relationship between test questions and concepts (referred to as attributes) and students taking the test were assigned knowledge states based on their test answers and the constructed q-matrix ((see Ham85 for a discussion of item-response theory))
  
-{{:​knowledge_assessment:​qm.jpg}}+
  
 The goal of q-matrix construction is to extract underlying, or latent, variables, which account for studentsí differential performance on questions. The goal of q-matrix construction is to extract underlying, or latent, variables, which account for studentsí differential performance on questions.
knowledge_assessment/q-matrix.txt · Last modified: 2023/06/19 18:03 (external edit)