What is Evidence-Centered Design?
The evidence-centered assessment design (ECD) framework was developed at Educational Testing Service by Mislevy, Steinberg, and Almond. The ECD framework explicates the interrelationships among substantive arguments, assessment designs, and operational processes.

What are Large-Scale Assessments?
Large-scale assessments are designed for large groups of examinees, typically numbering in the thousands, and often administered to make high-stakes decisions. In this project, we are focusing on the science part of the Minnesota Comprehensive Assessments—Series II (MCA-IIs), state tests that help districts measure student progress toward Minnesota's academic standards.

How is ECD Applied in ECDLarge?
The ECDLarge project aims to improve the approach to developing quality assessments of large-scale assessments by combining developments in cognitive psychology with advances in measurement theory and technology. (Learn more)

Circles of Expertise
ECDLarge brings together research expertise from four outstanding educational organizations: (Learn more)

• SRI International
• University of Maryland
• Pearson Education
• Minnesota Department of Education

Example Design Patterns
Various design patterns help guide the design of experimental investigations, observational investigations, and other assessments.

PADI and Evidence-Centered Design
The PADI project was precursor to the ECDLarge project. While the ECD framework explicates the interrelationships among substantive arguments, the PADI project provided higher-level schemas that built on national science standards (ETS’s ECD is content-free), limited statistical models to a family developed by Wilson and his colleagues, and provided supporting software tools for creating assessment designs within this framework.