Table 6 Categories in task-2 (usual)
Number of subjects using category labels (N 1 = 7) | Average size of category (N 2 = 15) | Number of problems accounted for (N = N 1 × N 2 = 105) | Number of problems wrongly accounted for (N* = 105) | Number of problems correctly accounted for (N C = N − N*) | |
|---|---|---|---|---|---|
Springs | 4 | 4.5 | 18 | 0 | 18 |
Inclined planes | 4 | 3.3 | 13 | 0 | 13 |
Balance of forces | 3 | 3.7 | 11 | 0 | 11 |
Conservation of energy | 3 | 6.0 | 18 | 9 | 9 |
Second law | 3 | 3.7 | 11 | 2 | 9 |
Pulley and string | 2 | 3.5 | 7 | 0 | 7 |
Circular motion | 4 | 1.5 | 6 | 0 | 6 |
Pendulum | 3 | 1.7 | 5 | 0 | 5 |
Simple harmonic motion | 2 | 2.0 | 4 | 1 | 3 |
Collision | 2 | 1.0 | 2 | 0 | 2 |
Inertial force | 1 | 1.0 | 1 | 0 | 1 |
Friction | 1 | 1.0 | 1 | 0 | 1 |
Others | 2 | 4.0 | 8 | 1 | 7 |