- Exploring Mental Models for Application in Networking Applications, Telephony and Environments


Guidelines --> Discussion

The theory behind these guidelines is conceptual design. Conceptual design is a design philosophy based on the belief that people have mental models of the world, and that they use their mental models as the basis of their interaction with the world around them. Some people have a mental model of they layout of their local supermarket, which means that they know roughly where in the store to go for the milk, bread etc. Other people don't, which means that they will have to walk up and down the aisles until they find what they are looking for. People with good mental models of their local supermarket are likely to be far more effective when going shopping than people without appropriate mental models of the store.

Mental models also apply to software. Users who have appropriate mental models (or users' models) of the application they are using, will be able to use the application far more effectively than if their users' models are flawed, patchy or non-existent. Users form their users' models on the basis of what they already know and the parts of the application they come into contact with, the system image (screen design, manuals, error messages, built-in help etc.). If, for example, a user has been using Netscape Communicator for a number of years, and decides to switch to Internet Explorer, s/he will be looking for the functionality s/he is used to from Netscape in Internet Explorer. That user's model of a Web browser will be shaped by his/her previous experience with Netscape.

Generally, a user does not need to have a user's model of how the application is implemented in order to use an application effectively. On the contrary - usability literature generally urge to design the system image to support the user's task. However, networked applications are a different matter. When using a volative distributed system with shared resources such as the Internet, it can be hugely beneficial to the network community and the user alike if the user has a simple user's model of how the underlying network works. This will help prevent wasted resources in terms of:

  1. Human resources, because users who are uncertain of basic Web browser behaviour are less likely to make full use of the Web in terms of e-commerce etc.
  2. Network resources, because users may inadvertently make a breakdown situation worse by an inappropriate recovery action.
  3. Financial resources, because of the cost of running customer helpdesks, and lack of revenue for e-commerce businesses.
These guidelines are based on the belief that communicating a simple model of the network in networked applications is necessary in order that the network is used effectively by everybody.

Last changed by L.Sheeran@cs.ucl.ac.uk on 30 August 2000