Assignment  # 04: Forcing Functions

General Task:

Working in teams of two, first define in your own words the concept of a forcing function. Then, being observant of the plethora of forcing functions in our everyday environment, identify and document some specific examples as delineated below.

Requirements:

1. Working in teams of two, first define in your own words the concept of a forcing function relative to the context of this course.


2. Give good examples of the following attributes in an interface:

   1. User v Machine Targeted
      1. Give an example of a forcing function that is aimed toward the user.
      2. In contrast, give an example of a forcing function that is applied instead to the inhibit the behavior of the machine.
   2. Overt v Subtle
      1. Offer an example of an overt, even blatant or heavy handed, forcing function, one of which the user is made consciously aware.
      2. In contract, give an example of a forcing function that is subtle, one that may well escape the user's awareness.

   3. Desired/Intended v Undesired/Unintended
      1. Give an example of a forcing function that has obviously been designed and implemented to affect the behavior of the user or machine.
      2. In contrast, furnish an example of a forcing function that is present in the interface but not desirable and probably not the product of a specific effort to provide it. That is, cite some negative interface characteristic that imposes an unwelcome forcing manifests an unwelcome, or even aversive, required behavior, one that specifically serves no positive function. This kind of undesired forcing function would probably be eliminated if it were reasonably feasible, but it most likely is crudely overlooked, hard to avoid because of other constraints like cost or physics, and so forth.

   4. Give an example of an interface that exhibits an undesirable, unproductive, forcing function, or an interface that would otherwise suffer from one were it not for a specific remedial effort to remove it from the interface. For example, suppose in regions of very low humidity a certain kind of rug is highly prone to inducing a strong static charge when someone walks across it while wearing leather soled shoes. Thus a "user" averse to receiving static shocks might feel inconveniently forced to remove his or her shoes, a situation we assume to be undesirable for the user. It also negatively affects the rug's sales. In summary, an an unintended forcing function might rear itself where it has not been intentionally introduced, and where it is desired by neither the user nor the interface designer/purveyor.

      In other words, all stakeholders concerned with the interface do not want the forcing function to be manifest. Its presence is a negative attribute for all parties. Maybe, in a later version the interface designers will have figured out a tractable improvement or retrofit that diminishes or removes the offending forcing function.

      Designs often have unintended negative consequences, right? Typically these arise from secondary effects that were not being considered. Here were are talking about an unintended, undesirable, forcing function. You are being asked to indentify one that remains, or one that has been clearly fixed through a targeted remediation effort by either the user of the designer. (Improvised user "fixes" sometimes can be amusing or actually dangerous.

      In subsequent product releases, say, the manufacture might have added an antistatic final treatment on the rug to alleviate the condition. Alternatively, the unhappy user might apply a consumer antistatic spray product to reduce or eliminate the static effect, and hence, suppress the forcing function that made her remove her shoes before walking on the rug.

   5. Well designed and Present v Poorly Designed or Omitted
      1. Give a poignant example of a particularly well executed forcing function.
      2. On the other side, offer an example of an interface egregiously lacking a forcing function, one that leaves the user exposed to making input errors of a more consequential type.

Submittal:

Make sure your submitted document shows the Standard Assignment Info Block at the top of the file.

It is important to name this exactly as indicated, because the file will be retrieved relying on this scheme. Departure from this naming template will cause the file to appear to not be submitted, and engender negative consequences.

Please assign the indicated filename and conform to the following syntax:

>handin

cs5540

assign_04

ForcingFunction.Lastname1.Lastname2.pdf

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