5. User test #1

We start by choosing professional users who rely heavily on the tools. We choose them from the industrial sectors and target countries in which the given tool is most widely used.

We then take exact measurements of each user's hand. We record each hand's length, width and strength. We use a gripping cone to measure gripping diameter: between thumb and forefinger, thumb and middle finger, and thumb and ring finger. Then we make a paper tracing of each hand.

Now for the test itself. The test must be performed exactly the same way every time. So the tool is delivered to each test user in the same way, in identical packaging. The explanation accompanying the test is the same for each user. And then the users try each prototype in turn, under realistic circumstances, according to a routine worked out by our researchers.

We document the performance of each tool with the help of video recordings, interviews and questionnaires. We also collect information on the way each user actually employs the tool and what he or she thinks of it. We seek both spontaneous reactions as well as opinions that have been thought-through. If a user feels pain, or unnecessarily high pressure at certain points, these points are carefully noted on the sketch of the user's hand.

We use a variety of methods to establish which tool the users prefer. Ranking, individual grading and eliminating prototypes by comparing pairs of tools are the most common. The shape, ease of manipulation and "graspability" of each tool are recorded and graded. In many cases, we also have to use other measuring methods. Thus we use EMG - electromyography - to measure muscular tension, and a goniometer to measure the position of users' hands.

The test period is an intense and critical time for our product developers, as well as for our ergonomists and industrial designers.