CLASS Tool Age Levels

The CLASS tool measures interactions in classrooms serving infants through high school students. That’s quite a span—and also why there are six different tools tailored to each age level. So what links these different tools? That’s where a fancy-pants term comes in: heterotypic continuity.

Simply put, effective classroom interactions across all these age levels share common features, but these features look different as children grow from infants to young adults. The CLASS tool considers development and context in its stage-appropriate descriptions of those features and groups them into domains and dimensions. So, the CLASS is similar across age levels, but not identical.

Let’s look at one dimension—Teacher Sensitivity—to see what I mean. Broadly speaking, Teacher Sensitivity describes teachers’ awareness of and responsiveness to children’s needs, and then looks at how comfortable children are in the classroom.

  • For infants, the teacher might attend to infants physically, soothing and calming them as a result.
  • In a K-3 classroom, the teacher might notice students who need extra attention and support and provide it to them, resulting in children taking academic or social risks, such as approaching the teacher for help.
  • In a secondary classroom, the teacher might check in with students to gauge their understanding and help them resolve problems. As a result, students take risks in the classroom, whether it’s tackling a challenging assignment or volunteering answers.

Can you see the similarities across age levels? The teacher supporting an infant who wants to pull to stand is demonstrating the same sensitivity as the teacher helping students complete complex trigonometry calculations. They’re both very aware of and responsive to individual needs, looking around to see how the infants or students are doing and quickly responding to any issues—and the infants and students show their comfort level with the teacher in similar ways—looking at the teacher and taking that risk to stand or ask for help. That’s heterotypic continuity!


Learn how CLASS works in Kindergarten through 12th grade