Table of Contents
In this chapter, we'll explore the various tools in CTAT that allow you to create and test tutors.
A problem for a student to solve is described in a behavior recorder data file, or BRD file. It stores the steps students should take (or shouldn't take) as links in a node-link graph. Links in the graph represent action that can be taken by the student or the tutor (in the case of a tool-performed action). Nodes in the graph represent stopping points between actions; they store no information about problem-solving.
A link can represent one of four different action types: correct, incorrect, and suboptimal. These terms are defined below.
A preferred, correct action. This type of link is traversed when matched with a student's action. A correct action link can have feedback associated with it that is displayed to the student when the link is matched; it can also have a variable number of hints that are displayed sequentially when the student requests a hint.
An incorrect action. This type of link is not traversed when matched. As one cannot progress 'through' an incorrect action link, it is not possible to have links beyond an incorrect action link. This type of link can have a variable number of 'buggy' messages that are displayed to the student when they perform the incorrect action specified on the link.
A correct action that is suboptimal. Unlike the incorrect action link, a suboptimal action link is traversed when performed. This type of link can have a variable number of 'buggy' messages that are displayed to the student when they perform the action specified on the link.
An incorrect action that is not modeled by the cognitive model. This type of link is used to identify errors that should not be traced by Jess, the rule engine used in Cognitive Tutor (Jess) mode, when running an automated test with the graph (ie, Test Cognitive Model on All Steps).