perspectives on developing and publishing clinical tests david s. herzberg, phd
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Perspectives on Developing and Publishing Clinical Tests
David S. Herzberg, PhD
A Career Path Less Travelled . . .
• PhD, Clinical Psychology, 1998• Post-Doc in NP, 1998-2000
• Chief Operating Officer• (VP R&D, 2009 – 2014)• (Project Director, 2000-2008)
Topics
• Overview of Test Publishing• Test Construction–Item Scaling–Norms Development
Test Publishers have a Trade Group!
• Certification/Licensure• Education• Industrial/Organizational• Workforce Skills Credentialing• Clinical
Clinical Publishers
Test Publishing Is A Process . . .
• Author: Acquiring IP through publishing contract• Planning: Deliverables, budget, timeline• R&D: Data collection, analysis, technical writing• Editorial: Optimize the text content• Design: Optimize the user interface• Technology: Online administration, scoring• Marketing: Present the work to an audience• Launch: Publish test for clinical use
Topics
• Overview of Test Publishing• Test Construction–Item Scaling–Norms Development
How Difficult Is A Test Item?
WISC-IV Comprehension9. Tell me some reasons that you should turn off lights when no one is using them.
• Sample A: Typically developing 4th graders– 90% ≥ 1-point response
• Sample B: 2nd graders with moderate ADHD– 30% ≥ 1-point response
Rasch Measurement Principles
• Also called IRT, single-parameter models• Assumes unidimensionality of measurement• Single numerical measure for both item
difficulty and person ability– Logit scale: mean = 0, SD = 1– Can be transformed
• “Sample-free” measurement
Rasch Probability Function
Item Characteristic Curve
Item Information Function
SIPT Space Visualization Item Map
Topics
• Overview of Test Publishing• Test Construction–Item Scaling–Norms Development
Normative Reference Samples
Normal Curve and Standard Scores
Are these norms?
Normally Distributed Test Scores
Skewed Distribution Within Narrow Age Band
Skewed Distributions Within Age Bands Lead To Nonsensical Standard Scores
Age Year Raw Score Mean SD
6 45 8
7 47 4
8 49 9
9 51 7
Example: Raw Score = 40• Age 7 years, 11 mo, 29 days: SS = 74• Age 8 years, 0 mo, 1 day: SS = 87 ????
Using Excel To Smooth Means, SDs
Inferential Norming
