Measures Developed by Robert C. Pianta, Ph.D.

Classroom Assessment Scoring System™ (CLASS)

CLASS is an observational instrument developed at the School’s Center for Advanced Study of Teaching and Learning (CASTL) to assess teacher-student interactions in PK-12 classrooms and in settings serving infants and toddlers.  It describes multiple dimensions of interaction that are linked to student achievement and development and has been validated in over 6,000 classrooms.  CLASS can be used to reliably assess classroom quality for research and program evaluation and also provides a tool to help new and experienced teachers become more effective.

Six versions of CLASS have been developed:

  • Infant
  • Toddler
  • Pre-K
  • K-3
  • Upper Elementary
  • Secondary

The CLASS system began as part of a national study in early childhood development.  Eventually, that research grew in significance as educational policies shifted focus to K-12 teacher accountability.  The CLASS instrument became a much-needed tool that could both effectively measure teacher-student interactions in a classroom setting and offer resources for strengthening those interactions across any subject area or age group.  CLASS is the only observational teacher assessment tool that captures teacher behaviors linked to student gains and that has been proven to work in tens of thousands of classrooms, from preschool to high school and beyond.  The CLASS tool includes cycles of 15-minute observations of teachers and students by a certified CLASS observer.  Those observations produce ratings (1-7) on dimensions of teacher-child interactions using a manual of behaviors and responses. 

Research conducted in over 6,000 classrooms concludes that from pre-K programs into the third grade, children in classrooms with higher CLASS ratings realize greater gains in achievement and social skill development.  Current work focuses on expanding the CLASS into infant and toddler classrooms as well as validation work on upper elementary and secondary versions of CLASS.  CASTL also supports the implementation of CLASS as a part of national (Office of Head Start), state (e.g., Virginia, Georgia, Arizona), and local (e.g., San Diego, Cal.) efforts to measure and improve early childhood education, and other versions are being used in K-12 teacher evaluation programs in Kansas and in large-scale evaluations by American Institutes for Research. CLASS was also part of the Gates Foundation's Measures of Effective Teaching study.

Additional CLASS resources for education practitioners and information about ongoing or completed research about CLASS is available through the Center for Advanced Study of Teaching and Learning. 


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Additional Measures

Included below are three measures developed by Pianta, along with manuals explaining their use and related articles.  There is no charge for the use of these measures in educational research.  No wording or rating scales of any items on the measures should be modified.  It is permissible to translate a measure for use in educational research; please send a copy of completed translations to  Permission is also granted to publish studies in which one of the measures has been used.

Student Teacher Relationship Scale (STRS)

The STRS is a teacher-report instrument designed for teachers of children between the ages of 3 and 12 which measures a teacher’s perception of conflict, closeness, and dependency with a specific child.

Reaction to Diagnosis Interview (RDI or RxDx)

The RDI is a standardized, reliable interview asking parents to describe their diagnostic experience of a chronic disability in their children. Based on their responses, parents are classified as either 'resolved' or 'unresolved' with regards to the child's diagnosis. This measure is no longer used or supported in Pianta's research, but may be used at no charge.

Child-Parent Relationship Scale (CPRS)

The CPRS (Pianta, 1992) is a self-report instrument completed by mothers or fathers that assesses their perceptions of their relationship with their son or daughter.  The 15 items are rated on 5-point Likert scales and the ratings can be summed into groups of items corresponding to conflict and closeness subscales.  It is applicable to children ages 3-12. This measure is no longer used or supported in Pianta's research, but may be used at no charge.