• Mental models

When I was observing the participants as they tested my prototype, I noticed that two of them had problems starting the game. The instructions displayed on the screen read "Click on red dot to start the game". Instead of just clicking the red dot once, they clicked on the dot but held down the button and proceeded to drag the mouse down the maze. They soon realised that the game didn't start and tried again.

It didn't occur to me that people might have their own assumptions as to how the game should be played. To prevent this, I should have considered mental models used in Human-Computer Interaction. Khella (2002) explained that on the users' side, it will consist of users' physical and sensory abilities, their previous experience dealing with similar systems, their domain knowledge and finally ergonomics and environments in which users live. While at the designers' side, "the need is to influence the user's model to perceive the conceptual model underlying the relevant aspects of the system" and "this can be accomplished using metaphor, graphics, icons, language, documentations and tutorials" (Khella, 2002). These materials should collaborate together to encourage the same model.


Relating this back to the scenario I encountered, there was a breakdown in the designer's model of the user's model. I was wrong to assume that the instructions for the game were clear and that people might have their own perceived way of going about things. This misconception led to confusion in the players.

From this I have learnt that it is important to look at the design through the player's perspective and not be preoccupied with the designer's perspective. Insights gained from this would help me understand how mental models can affect the usability of my designs in future work.

References
Khella, A. 2002. Knowledge and Mental Models in HCI. http://www.cs.umd.edu/class/fall2002/cmsc838s/tichi/knowledge.html (accessed May 25th 2006)