SLIDE 1 PARCC Diagnostic Assessments for Mathematics Comprehension: A Diagnostic Classification Model Approach
Laine P. Bradshaw
The University of Georgia
June 24, 2015
SLIDE 2
- A brief introduction to diagnostic classification models
(DCMs)
» How are they different from the models that are typically used in assessment? » Why are they particularly useful for diagnostic assessments?
- How did we use the DCM framework to develop PARCC’s
diagnostic assessment system for mathematics comprehension in Grades 2-8?
- What new challenges in reporting exist when
transitioning to a new psychometric framework?
Overview
SLIDE 3
Big Picture: Math Content to be Measured
SLIDE 4
Typical End of Grade Summative Test
SLIDE 5
- Traditional testing procedures measure an overall
ability in an area with a continuous latent variable
7th grade Math Ability
Cluster 4 Item
Math ability is continuous Responses to items are observed The more math ability a person has the more likely he or she is to answer an item correctly
Traditional Measurement Models for Summative Tests
Cluster 2 Item Cluster 1 Item Cluster 3 Item … Cluster 2 Item
SLIDE 6 Traditional Testing and Classification Methods
- Information from Continuum:
» Spencer has more math ability than Sue » Hugh scored a 240 on the test » Juan scored in the 70th percentile
- Diagnosis from Cut Score:
» Sue scored below the cut score » Sue is not proficient in 7th grade math Not Proficient
7th Grade Math Ability
Proficient
HIGH LOW
Question difficult to answer: What are Spencer’s weaknesses?
7th grade Math Ability
Cluster 2 Item Cluster 6 Item Cluster 1 Item Cluster 3 Item
…
SLIDE 7
Diagnostic Approach
Instead of measuring an overall math ability in 7th grade, we can break “math” down into a set of skills or attributes: Cluster 1 Cluster 2 Cluster 3 Cluster 4
SLIDE 8 Cluster 1
Diagnostic Approach
Cluster 4 Item Cluster 2 Item Cluster 1 Item Cluster 3 Item … Cluster 2 Item
Cluster 2 Cluster 3 Cluster 4
Each cluster has two levels A student can be in one of two groups, or levels, for each cluster
- Higher group (masters; on-track)
- Lower group (non-masters; needs attention)
Masters are more likely than non-masters to answer items correctly.
SLIDE 9 Diagnostic Classification Models
Subtract Add Multiply Divide Masters Non-masters
- DCMs uses responses to items to place students into groups
according to multiple skills
–No cut score is used to put students into groups; the model is built to do that
Cluster 1 Cluster 2 Cluster 3 Cluster 4
SLIDE 10 Diagnostic Classification Models
Subtract Multiply Divide Add
- Students receive attribute-specific feedback
- The model provides a probability each attribute is mastered
- Notice there is no “score” in a traditional or grading sense
Spencer has mastered Cluster 1 and 2, but should improve his understanding
.84 .76 .35 .28
Cluster 1 Cluster 2 Cluster 3 Cluster 4
SLIDE 11
- Aligns with a standards-based view of achievement
where mastery of all standards is monitored
» Modeling multiple “dimensions” or traits » Instead of answering: Did this student meet the standards? » Answer: Which standards has the student met?
- DCMs provide valuable information with fewer data
demands
» Higher reliability per dimension than IRT/MIRT models » Potential to drastically reduce testing time » Quick and dirty categorical feedback
Benefits of Using DCMs
SLIDE 12 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 3 13 23 33 43 53 63 73 83 93 Reliability Number of Items
DCM IRT
DCM Reliability
8 Item Reliability
Templin, J., & Bradshaw, L. (2013). Measuring the reliability of diagnostic classification model examinee estimates. Journal of Classification, 30(2), 251-275.
SLIDE 13
Psychometric Approach for Mathematics Comprehension
Non-summative Assessments
SLIDE 14
Mathematics Comprehension
SLIDE 15
Example: Cluster Level Attributes in Math
Number Systems Learning Progression Attribute 1: Divide Fractions Attribute 2: Understand Rational Numbers Attribute 3: Operate with Rational Numbers
SLIDE 16 Example: Cluster Level Attributes in Math
Number Systems Learning Progression
- Create a separate diagnostic test for each individual
cluster
… … …
Divide Fractions Understand Rational Numbers Operate with Rational Numbers
SLIDE 17 Diagnostic Feedback to Students
Divide Fractions Understand Rational Numbers Operate with Rational Numbers
Number System Results Diagnostics
Example Student A Example Student B Example Student C
On-track Needs Improvement
Diagnostic Key:
Mastery Probability
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
SLIDE 18
Key to Flexible Diagnostic Assessment System: One Test Per Cluster, Packaged in Different Ways Individual Cluster Test 1 attribute ~8 items
SLIDE 19
Key to Flexible Diagnostic Assessment System: One Test Per Cluster, Packaged in Different Ways
Grade Level Test 6 attributes ~48 items
SLIDE 20
Key to Flexible Diagnostic Assessment System: One Test Per Cluster, Packaged in Different Ways
Learning Progression Test 6 attributes ~48 items
SLIDE 21
Key to Flexible Diagnostic Assessment System: One Test Per Cluster, Packaged in Different Ways
Grade Level Test 6 attributes ~48 items Learning Progression Test 6 attributes ~48 items Individual Cluster Test 1 attribute ~8 items
SLIDE 22
- DCMs do not provide a score!
» They provide classifications
- How will teachers and students interpret classifications?
- How will they interpret the probabilities of mastery?
- What is the best way to present the results so that
interpretations are clear and accurate?
Challenges in Reporting
SLIDE 23
- Teachers can monitor the percentage of students who
have mastered each cluster for a given grade level
» Aggregate feedback
At the class level
SLIDE 24
- Can show the multidimensional mastery profiles for
each student in the class
- Who has mastered each cluster?
At the class level
SLIDE 25
probability of mastery be provided? Where?
» Analogous to decisions for where to put standard errors on score reports for IRT-based assessments
At the student level
SLIDE 26
- DCMs are parametric, latent class models
» Other examples of these models exist » For example, Bayes Nets
- Models in the same family produce the same student
estimates—mastery classifications and probabilities of mastery
» These models face similar challenges in reporting
Classification-based Reporting
SLIDE 27
Please feel free to contact me with any questions or comments: laineb@uga.edu