HCI and the challenges of mass communications

XI.2 March + April 2004
Page: 76
Digital Citation

The future’s here;

Lorenzo Wood, Luke Skrebowski

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The pace of innovation in the technology industry means that people are constantly presented with new things to learn and asked to adopt things for which they often have not expressed a direct need. Unsurprisingly, most people cope by switching off and getting involved only with that which they are forced to. Although the future surrounds us, most people live in versions of the past. As Marshall McLuhan observed, "We look at the present through a rearview mirror. We march backwards into the future" [3].

So, how do we change this? More than anything else we need to help people understand how they can make use of technology.

We have used the concept of affordances to help us design for ease of understanding. Affordance is a concept originally proposed by the psychologist J.J. Gibson [2] and popularized in the design community by Donald Norman. In Norman's view, affordances "refer to the perceived and actual properties of the thing, primarily those fundamental properties that determine just how the thing could possibly be used" [4]. Unfamiliar things are much easier for people to use when their affordances perceptibly match their functions.

We applied the notion of affordances to the design of new media to see if this could help us design complex, layered interfaces onto interactive media content. We observed that the functional apprehension of any piece of media (for instance, newspapers, television, or Web sites) depends on a relationship between the user and her individual perception of each of its component. For the kinds of interactive media with which we work—personal computers, Web browsers, mobile phones—the number of nested components making up any given instance is significant (e.g., PC, operating system, browser, interface, content). As a result, the range of users' apprehensions of any given piece of interactive media is also wide.

Often, functional apprehension of a given technology is not perceptible. An extreme example: To an experienced user, a PC affords a great many things—communication, creation, sharing—but to someone who has never seen one before, a PC is an anonymous box that affords nothing at all.

When considering how to apply affordances to improving the functional apprehension of new media, Norman runs into problems because his definition relies heavily on the perceptible properties of the thing in question. Consequently, we looked for a more nuanced definition of the term and found it in work by Bill Gaver on the affordances of technology [1]. Gaver's definition of affordances as "properties of the world defined with respect to people's interactions with it" allows for the concept of hidden affordances—those that exist but that people are not able to perceive (see Figure 1).

This matrix allowed us to focus on how the "hidden" affordances of the various components we use in our design work can be made perceptible to the user. We chose two classes of problem that we commonly face in designing new media: replacement and complement. Here we demonstrate how we might apply this definition of affordances to the first class of problem using real-world examples. (See www.oyster.com/affordances for a demonstration of how we applied this technique to complementarity of design.)

We are often asked to design something that replaces or partly replaces something that already exists. An important thing to consider when doing this is how to introduce the new thing, particularly to satisfied customers of the existing product or service. We look here at how the TiVo was unsuccessfully introduced to the British market and how it might have been done differently.

TiVo is a "personal video recorder" (PVR), a device that uses a hard disk to store television programs to be watched later. Many users of TiVo become great enthusiasts because it is a device that gives users greater control over their television viewing.

The trouble is, it's not easy to communicate this. If you have never used a TiVo, this description has probably not convinced you. In the United Kingdom, TiVo initially ran a national advertising campaign that concentrated on one "killer" feature (the ability to "pause" live TV). This campaign failed to generate many sales. Conscious that they needed to find a better way to get across what TiVo was, they hit upon a simple and easy-to-understand description: "a VCR without tapes." However, this, too, was unsuccessful. Why?

We used our understanding of affordances to analyze this problem. We started by comparing and contrasting the affordances of a VCR and a TiVo. Initially, we wrote down the affordances we could think of for each (see Figure 2 for a list of affordances of a VCR).

We then grouped the affordances in two ways (Figure 3):

  1. Whether affordances related to the physical form, the functionality (which we called "affordances of the medium"), or the higher-level goals of users (which we called "social affordances")
  2. Whether the affordances were an intentional part of the original design or an unintended consequence of it.

Because we were analyzing a replacement problem, we looked at the differences in the affordances between the two devices. In particular, we wanted to know which affordances we gain when we replace a VCR with a TiVo, and which we lose. We modeled this by crossing out the affordances on our lists that were common to both and looking at the differences. Even though our lists of affordances were not comprehensive, we found some interesting results when looking at just a subset—the intentional, social affordances of both devices (see Figure 4).

Undoubtedly TiVo affords some useful and compelling features that are unavailable with a VCR. However, the affordances unique to the VCR are all very important (renting, sharing, and collecting recordings); moreover, they're all consequences of having separate tapes. In this light, the positioning of TiVo as a "VCR without tapes" seems flawed. Since switching from VCR to TiVo appears to the consumer as a replacement scenario, this kind of comparison is inevitable, and the TiVo looks like a poor choice as a result.

Sidebar. A Methodological Framework for Putting Affordances into Practice

In practice, TiVo is not meant to replace the VCR. It is designed to provide more and better functionality for time-shifting TV programs (which is only one of the things that a VCR affords). It is effectively a self-scheduling machine.

Undertaking a quick exercise like this, focusing on the affordances of the devices in question, enabled us to uncover key flaws in the positioning of the TiVo. These errors could have been avoided had TiVo's marketers had an understanding of affordances.

Faced with the same problem, we would have suggested an alternative positioning "TiVo—the best thing next to your VCR."

[Footnote, December 2003: This season, Sky has been heavily promoting its own PVR, Sky+. The promotional tag for its campaign is "Create your own TV channel," which is close in concept to our suggestion and apparently much more successful.]

back to top  References

1. Gaver, B. Technology affordances., In Proceedings of CHI'91, New Orleans, Louisiana, ACM, 1991.

2. Gibson, J.J. The Ecological Approach to Visual Perception. Houghton-Mifflin, Boston, MA, , 1979.

3. McLuhan, M. The Medium is the Massage. Bantam Books, New York, 1967.

4. Norman, D.A. The Psychology of Everyday Things. The MIT Press, Cambridge, MA, 1988.

back to top  Authors

Authors' Bio

Lorenzo Wood is chief scientist of Oyster Partners, where he is responsible for research and development. His own research interest is in the social impact of technology. He is a graduate of the Computer Laboratory at Cambridge University.

Luke Skrebowski is an experience architect at Oyster Partners. He has a particular interest in how interactive technology is changing the mass media and has consulted to the Guardian Group and the BBC on this topic. He is a graduate of Cambridge University.

back to top  Figures

F1Figure 1. Matrix of affordances (adapted from [1]).

F2Figure 2. Some affordances of a VCR and tapes.

F3Figure 3. Intentional and unintentional affordances of a VCR and tapes.

F4Figure 4. Intentional, social affordances of a VCR compared with a TiVo.

back to top  Sidebar: A Methodological Framework for Putting Affordances into Practice

A simple methodological framework for incorporating affordances into the design process is as follows:

1. Make a list of affordances for an existing or planned design. This should be a quick process, rather than an exhaustive one. The 80/20 rule applies here.

2. Group and organize the listed affordances (physical, medium, and social; intentional and unintentional).

3. Use these affordances as criteria against which to rate the design; consider how design choices positively and negatively affect these affordances.

4. Optimize the design so that it best affords what it is meant to.

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