Experiment Setup

In order that the experiments were successful, an infrastructure was set-up to carry out assembly tasks. The prerequisites for such an infrastructure were rather simple: It should allow creating as many different tasks as were needed,

• All tasks had to be of a similar complexity degree,
• The assembly task should involve the use of manually or tool-assisted piece manipulation

The result was the platform highlighted in next figure:

The platform has the following characteristics:

• It allows defining multiple 3 dimension assemblies
• The tasks include the assembly of mechanical parts, the connection of electrical connectors and some kind of quality control checking, by means of gauges to measure some distances
• Workers have to use two different tools to screw the bolts
• The mechanical parts to assemble are three metallic parts of different shapes that can be orientated in different positions. The parts have to be assembled in both sides of a metallic panel where 100 holes have been drilled, creating a matrix of different metric holes.
• The task also includes connecting three pairs of BNC connectors by means of wires in a 4x4 connector matrix

Thanks to this platform we can define multiple different assemblies, all of them of similar complexity and as a consequence allowing comparing results.
The users had to assemble three different shaped metallic pieces into both sides of a panel where 100 holes of different metrics were drilled. The pieces were able to adopt different special orientations, and could be positioned at different relative distances among them. To check this distance a gauge had to be used. On the other hand, there was a 16 BNC connector panel, where the user had to connect 3 pairs of wires. Thanks to the platform it was possible to define multiple assembly tasks for the same user, and to compare the performances of the user when using different interaction modalities.