ABSTRACT
The second level of our ladder - the psychologicallevel - introduces a host of new data about human nature that Human-tech design must take into account if it's to lead to fluent, productive interaction between people and technology. A particular technology may be well suited to our physical abilities, but products or systems that pose too much of a burden on our limited memory capacity, that are too complex or counter-intuitive for us to understand, or that violate our mental expectations about cause-effect relationships will fail to pass Robert Wright's test of "affinity with human nature:' Other products or systems, those that are tailored to these psychological considerations, create a close
bond between person and technology, and lead to a single, tightly integrated system, which can be so effective that the technology itself becomes transparent. Like a blind man with a cane, we don't have to think explicitly about the technology, and are free to focus on pursuing our goals.
