What is Quality in Use

As we are witnessing an increase in multifunctionality of interactive devices, two problems are taking shape in user interface (UI) design: first, the problem of complexity, and second, the problem of fragmentation (Kljajevic, in press). The former is reflected in the fact that multipurpose interactive devices usually have interfaces that do not allow easy access to new functions and features, rendering the increased functionality useless. The second problem is related to the fragmentation in the current research paradigms and testing trends that inform UI design. These paradigms and trends stem mostly from psychological theories that focus on only some specific aspects of user-interface interaction. While it is important to investigate such topics in detail, it is even more important to look at the totality of the interaction and determine the principles that operate in it. An integrative approach to UI design has the potential to solve both problems. Such an approach has two components: a top-down and a bottomup component. Its top-down component deals with a small set of basic cognitive principles that operate in interactive reality and therefore need to be recognized at the level of UI design. The principles are built into a cognitive architecture—a wide theoretical framework that corresponds to the human cognitive system—whose constraints prevent proliferation of implausible theories, which solves the fragmentation problem.