HCI’s Teachings on Transparency I

I’ve gone back to basics and have been reading through the HCI bible (Human Computer Interaction 3rd Ed. Dix et al.) to get a better understand how transparency is conceived of in interactive systems. System transparency does get a treatment as an element of formal interface modeling. There are several key points that we can learn from and which tie into transparency as it concerns journalism and interactive media.

While the state of the system is central to the notion of system transparency, what we’re really interested in is an idealization of the system state. What’s important in a user-centric model is the representation of “state required to account for the future external behavior.” In the text Dix refers to this as the “effect” which I think is nasty terminology. I’m going to call it the “User-Relevant State” or URS.

They do arrive at a workable definition of state: “[Transparency] would say that there is nothing in the state of the system that cannot be inferred from the display. If there are any modes, then these must have a visual indication; if there are any differences in behavior between the displayed shapes, then there must be some corresponding visual difference.” This gets at the central usability heuristic of observability and its relation to transparency. Observable states are visually shown in the interface; an invisible component of the URS does not uphold the principle of system transparency. One could make an argument that if the URS is not fully transparent usability problems are likely to ensue since the user does not have adequate feedback on the state of the system relevant to its usage.

Of course, not all of the URS may be observable in one view because of screen real-estate problems and that the display could be unintelligible if there were too much shown. Thus the URS can be progressively observed through interaction (e.g. clicking a marker and an object for state or displaying a layer over objects which explicates state). The usability of a system and its effectiveness may however be increased if more of the URS (such as data dimensions in a model) is visible in the display in one view. A key connection Dix makes is that when the user can observe the complete state of the system they can (in theory) predict what the system will do. This is precisely what many simulation games are all about: predicting how actions taken on the model will impact on future states of the simulation. The question remains: does complete transparency make a game experience too easy? Isn’t there some satisfaction in figuring it out?

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