# The Glossary of Human Computer Interaction

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The task-artifact cycle (artifact can also be spelled artefact) captures the idea that tasks and artifacts coevolve (Carroll et al. 1991). The cyclical relationship between the two can be described as follows: A given task sets requirements for the design of an artifacts to help an individual perform the task. The resulting artifact, in turn, creates new or uexpected possibilities or pose new constraints on the performance of the task. These possiblities and/or constraints often suggest a revision of the original task for which the artefact was made. The new task sets new requirements for the redesign of the artifact and so on and so on (de Lëon 1999). The task-artifact cycle is in other words an iterative process of continuous, mutually dependent development between task and artifact, a process that will never reach an optimum state.