Brief statement of principle
Post-practice reflection involves activities that follow successful completion of a quantitative problem aimed at helping students to understand the concepts associated with that problem and to develop abstract problem-solving schema. Such schema are a kind of knowledge component that if acquired with high feature validity will help students with solving similar (near transfer) problems, and perhaps also far-transfer problems.
Post-practice reflection activities often involve some kind of dialogue between the student and another agent (teacher, peer, or computer tutor).
Here is a sample Reflective Dialogue, incorporated within the Andes physics tutoring system (VanLehn et al., 2005):
An example of a Post-Practice Reflective Dialogue
ANDES PROBLEM ROTS4A: A 5.00 kg ball is attached to a 2.00 m rope which will break if the tension exceeds 100 N. If the ball is made to swing in a vertical circle, what is the maximum velocity with which the ball can pass through the lowest point?
One way to start is to ask ourselves, “What quantity is the problem seeking?”
In this case, the answer is the magnitude of the force on the particle due to
the electric field.
We know that there is an electric field. If there is an electric field,
and there is a charged particle located in that region, then we can infer
that there is an electric force on the particle. The direction of the
electric force is in the opposite direction as the electric field because
the charge on the particle is negative.
We use the Force tool from the vector tool bar to draw the electric force.
[ PROMPT ]
This brings up a dialog box. The force is on the particle and it is due to some
unspecified source. We do know, however, that the type of force is electric, so
we choose “electric” from the pull-down menu. For the orientation, we need to
add 180 degrees to 22 degrees to get a force that is in a direction that is
opposite of the direction of the electric field. Therefore we put 202 degrees.
Finally, we use “Fe” to designate this as an electric force.
Now that the direction of the electric force has been indicated, we can work on
[ PROMPT ]
finding the magnitude. We must choose a principle that relates the magnitude
of the electric force to the strength of the electric field, and the charge on the
particle. The definition of an electric field is only equation that relates these
three variables. We write this equation, in the equation window.
Note. PROMPT = "Please begin your self-explanation."