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.

Theme table
 

Presentation