Last Update 11/ 09/ 2002
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Educational games are here considered as an alternative technique for online student evaluation. This technique involves the student in the pleasant and exciting atmosphere of the game. The individuals' intention to reach a nice score keeps attention and motivation high. With this resource time will be invested in constructive activities related with symmetry operation (SO) and projection of three dimensional structures.
To accomplish this objective five interactive applications are presented
with increasing difficulty from left to right, you may click on any link
given in the sequence below.
| tetrahedron | cube | octahedron | dodecahedron | icosahedron |
The challenge is to choose a suitable click sequence on the SO buttons on the selected polyhedron to move the blue colour of one edge and paint other edges until all are blue.
Each polyhedron is initiated randomly, the number of different starting
possibilities for each case is equal to the number of edges, as can be
observed on the table below. Each possibility is here named as a game,
thus tetrahedron has only 6 games.
| tetrahedron | cube | octahedron | dodecahedron | icosahedron |
| 6 | 12 | 12 | 30 | 30 |
All the games may be started again by a click on the centre of the figure.
Whenever a game is completed the program displays the starting and ending time on top and bottom, respectively.
Students of the crystallography discipline of Federal University of
Vicosa, Minas Gerais, Brazil solved selected SO games during a class activity,
related results recorded by an especial application are presented in the
table below.
| polyhedron | # students | # games | minimum key hits to solve | minimum time to solve (s) |
| tetrahedron | 11 | 6 | 2 | 1 |
| cube | 12 | 12 | 2 | 1 |
| octahedron | 8 | 6 | 2 | 1 |
| dodecahedron | 12 | 11 | 4 | 2 |
| icosahedron | 8 | 8 | 5 | 3 |
Note in column "# students" in the table just above the student's preference for cube and dodecahedron. All the possible different starting games in tetrahedron and cube were solved, as indicated in column "# games". Higher number of edges demands more key hits and consequently more time to solve the game.
The animation below shows random sequences of key hits for the cube.
Bibliography
SHUBNIKOV, A. V. and KOPTSIK, V.A., Symmetry in Science and Art, Plenum Press, N.Y.,1974.
SMART, L. and MOORE, E., Chapman & Hall, London, 1995.
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Table of subjects.