A Tutoring System That Simulates the Highly Interactive Nature of Human Tutoring

ion/specification relations Abstract:instance (instance:abstract): S2 instantiates the abstraction stated by S1, or S2 abstracts over the information presented by S1. Tutor: How can the acceleration be 0 if there are forces on it? Student: The sum of the forces equal 0 for there to be no acceleration. Tutor: That’s exactly right. The weight and the normal force are (in this case) equal and opposite. Explanation: “In this case” (as the tutor says), the weight and normal force being equal and opposite represent an instance of the abstraction “sum of forces equal 0.”instance (instance:abstract): S2 instantiates the abstraction stated by S1, or S2 abstracts over the information presented by S1. Tutor: How can the acceleration be 0 if there are forces on it? Student: The sum of the forces equal 0 for there to be no acceleration. Tutor: That’s exactly right. The weight and the normal force are (in this case) equal and opposite. Explanation: “In this case” (as the tutor says), the weight and normal force being equal and opposite represent an instance of the abstraction “sum of forces equal 0.” Set:member (member:set): S2 presents a member of the set referred to by S1, or S2 names the set to which an item mentioned by S1 belongs. Tutor: What does the problem ask for? Student: The magnitude of the acceleration Tutor: What type of acceleration? Student: Average Explanation: The tutor refers to acceleration as a set and prompts for a member of that set; the student gives the type of acceleration asked for in the problem. Whole:part (part:whole): S2 names a part of an object that S1referred to, or S1 names a part of an object named by S2. (In physics, “parts” are often vector components or the specific forces acting on an object.) Student: Acceleration would be plus. Tutor: Right, the x component of the acceleration would be plus. Explanation: The student names a vector (acceleration); the tutor refers to a specific component of that vector. Process:step (step:process): S2 presents a step that follows from the process or line of reasoning described by S1, or S2 describes the line of reasoning that leads to the step described by S1. Student: The acceleration is 0. Tutor: So then m a 0 Fnet T W and hence T W. Explanation: The student gives a step in a line of reasoning; the tutor expands the line of reasoning (process) that follows from that step. Object:attribute (units, direction, magnitude): S1 names an object or value; S2 specifies a property of that object—in particular, its units, direction, or magnitude. Student: Velocity is 14. Tutor: Right, 14 m/s. Explanation: The student provides a value for velocity; the tutor specifies its units. Term:definition (definition:term): S2 defines a term mentioned by S1, or S2 labels a statement by S1 with an appropriate term. Tutor: What is the definition of the average acceleration (in words or in mathematics)? Student: A (Vf Vo)/Tf To. Explanation: The tutor prompts the student to define average acceleration; the student does so. General:specific (specific:general): S2 names a state, object, or action that is related to the content in S1 but is more specific, or S2 is more general than the state, object, or action referred to in S1. Applies when none of the preceding relations apply. Student: Average acceleration can vary. Tutor: Right; it can go up above the average and down below it. Explanation: The tutor specifies how acceleration can vary. Other commonly occurring relations in physics tutoring Condition:situation (situation:condition): (a) S1 presents a condition or set of circumstances, and S2 states the situation that stems from or coincides with those conditions, or (b) S1 presents a situation, and S2 states the conditions or circumstances that explain that situation. Tutor: When do kinematics equations apply? Student: When the acceleration is constant. Explanation: This relation could be stated in conditional form: if acceleration is constant, then the kinematics equations apply. Compare: S2 compares an object, situation, or value referred to by S1 with some other object, situation, or value. Tutor: What is the net force that the air bag imparts to the driver? Student: Equal to the force the driver applies to the airbag. Tutor: Same direction? Student: No, opposite direction. Explanation: The tutor prompts the student to compare the value and direction of two. T hi s do cu m en t is co py ri gh te d by th e A m er ic an Ps yc ho lo gi ca l A ss oc ia tio n or on e of its al lie d pu bl is he rs . T hi s ar tic le is in te nd ed so le ly fo r th e pe rs on al us e of th e in di vi du al us er an d is no t to be di ss em in at ed br oa dl y. 1129 TUTORING SYSTEM