The variability or flexibility of delivery during the presentation of a lesson by a teacher is called

The variability or flexibility of delivery during a lesson is called instructional variety.

Instructional variety means varying methods, media, questions and pace to keep learners engaged.

Thinking curriculum refers to a curriculum designed to develop higher-order thinking, not to delivery flexibility.

Comprehension is the level of understanding a message, an outcome rather than a delivery style.

Procedural knowledge is knowing how to perform a task, a type of knowledge not a mode of presentation.

Instructional variety is one of Borich's key effective teaching behaviours, alongside clarity and engagement.