9. Problems with the Model Human Processor

Although the Model Human Processor has merit, it does not cover everything about the way a person deals with information. Consider these:

• If assumes that the person in only doing one thing at a time. It is quite common to be making a phone call and typing something at the same time or any other type of multi-tasking.
• It does not consider the effects of other people whilst the person is carrying out the task. For instance holding a conversation whilst interacting with the interface
• It does not deal with the environmental conditions the person is in. For example a telephone repair person, up a pole in the freezing cold, trying to make a test phone call, has an entirely different experience compared to a person calling in a comfortable office.

Nevertheless the MHP model has proven very useful in HCI design.