Constraints

-Limitations on human behavior–may be expressed as anything from simple suggestions to strict rules, or they could be only subconsciously sensed as natural aspects of the thing that a person is trying to do or create.

-We are always working in some set of constraints: the physical requirements of survival (air we breath, food and water); the limitations of language on verbal expression; the rules of social acceptability in public situations (wearing clothes). It is difficult to imagine life, even a fantasy life, in the absence of any constraints at all.

-Constraining people through limitations on input and output capabilities becomes less effective as the number of modes in the interface increases; separate sets of constraints for each mode serve to confuse and frustrate people.

-Humans working on computer-activities are subject to constraints such as technical capabilities and limitations of the system itself. For example, if a computer doesn't have a speech processing capability then a person must employ the keyboard for verbal input and is constrained by its vicissitudes (layout, presence or absence of function keys).

-People are constrained by the nature of the activity such as a word processor or drawing program; each program has different functions that allow users to do only a certain number of things. Constraints are necessary to contain the action within the mimetic world.


 * Types of Constraints:**

//Explicit-// undisguised and are directly available (menus or command languages). When we are in doubt about the "legality" of certain choices or actions, we can easily find the rules and protocols of a system as seen in an owner's manual or in an on-line "help" facility.

//Implicit-// identified when a system fails to allow us to make certain kinds of choices. For example, in word processors there is no facility that allows a user to "draw" or "paint" in the document, and the absence of these functions makes it less likely we will think about doing so.


 * Question for Further Thought:** What is the relationship between the experience of creativity and the constraints under which we perform creative acts?

Computers As Theatre
 * Helpful Illustrations:**

[|http://ai.uwaterloo.ca/~vanbeek/Constraints/constraints.html] [|http://kti.mff.cuni.cz/~bartak/constraints/]
 * Helpful Websites:**

Laurel, Brenda. //Computers As Theatre.// New York, Reading, Mass: Addison-Wesley Publishing, 1991.
 * References:**