Barring data transport problems, the reasons for the computer's inability to interact effectively can be traced back to a fundamental difference in the way humans and computers utilize information. There are many high level reasons but they can all be traced back to this: computers must classify information whereas humans may categorize.  T    (23R)

When the computer is viewed as having intention "the personification of the machine is reinforced" (Suchman). The interaction between the user and the computer is the locus of negotiation for performing the task. The computer takes a privileged stance, above the task. When in that stance we expect the computer to truly have, given the intention we have granted it, the intelligence, inferential power and adaptability that Suchman says we expect in social interaction. This is unfortunate because the computer is not intelligent; it cannot compare arbitrary and dynamic categories. It has no true and general inferential power; it cannot create links between categories. It is not truly adaptable; it can only create new classes of distinction according to a limited rule set. The expectation of intelligence sets up a poor mental model of the real situation. Such a model cannot be run to "predict the output which would result from some kind of input" (Eberts, 1994).  T    (23T)

Paradoxically, the intention that grants the high expectation of intelligence creates lower expectations of effective performance. We perceive an obscure purpose in the computer that we must decode and any difficulty in doing so must be our fault. When our interaction with the computer fails we think it is because we are unable to communicate as it does. As Norman (1988) says, when we should be blaming the design we are blaming ourselves.  T    (23U)