The comparability of measurements made in differing circumstances by different methods and investigators is a fundamental pre-condition for all of science. Successful applications of technology require comparable measurements. While the applications herefocus on educational tests, score linking issues are directly applicable to medicine and many branches of behavioral science.

"The comparability of measurements made in differing circumstances by different methods and investigators is a fundamental pre-condition for all of science. Successful applications of technology require comparable measurements. While the applications herefocus on educational tests, score linking issues are directly applicable to medicine and many branches of behavioral science.

Overview.- Overview.- Foundations.- A Framework and History for Score Linking.- Data Collection Designs and Linking Procedures.- Equating.- Equating: Best Practices and Challenges to Best Practices.- Practical Problems in Equating Test Scores: A Practitioner's Perspective.- Potential Solutions to Practical Equating Issues.- Tests in Transition.- Score Linking Issues Related to Test Content Changes.- Linking Scores Derived Under Different Modes of Test Administration.- Tests in Transition: Discussion and Synthesis.- Concordance.- Sizing Up Linkages.- Concordance: The Good, the Bad, and the Ugly.- Some Further Thoughts on Concordance.- Vertical Scaling.- Practical Issues in Vertical Scaling.- Methods and Models for Vertical Scaling.- Vertical Scaling and No Child Left Behind.- Assessments Linking Group Assessments to Individual.- Linking Assessments Based on Aggregate Reporting: Background and Issues.- An Enhanced Method for Mapping State Standards onto the NAEP Scale.- Using Aggregate-Level Linkages for Estimation and Validation: Comments on Thissen and Braun & Qian.- Postscript.