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By Gerd Waloszek, SAP AG, SAP User Experience – September 6, 2012
In her 2011 book Inventing the Medium – Principles of Interaction Design as a Cultural Practice, Janet H. Murray outlines a new (she calls it "innovative") framework for design, in which she adopts a humanistic instead of a social science or industrial design perspective. Murray regards this framework as a unifying framework for many disparate but related efforts and suggests that it helps speed the process of innovation because of its focus on core human needs and its intention to "focus designers' work on useful and lasting innovation" instead of on mere novelty.
Murray explains that digital designers have two responsibilities: "To create the artifact that best serves the needs of people who will interact with it, and to advance the digital medium as a whole." In her view, designers are engaged in a "collective design process," performing "the collective cultural task of inventing the digital medium," in other words, expanding "the meaning-making conventions that make up human culture" and "our ability to understand the world and to connect with one another." Read my review (in progress) of Murray's book for a closer look at her humanistic design perspective.
In this article, which complements that review (in progress), I want to briefly outline this approach and its humanistic design perspective because it differs considerably from typical HCI-oriented design approaches that currently dominate the UI design field. Please note that there is a certain overlap with the review.
According to Murray (2011), her new framework for design entails the following building blocks:
She calls her approach a "design practice," refers to it as "inventing the medium," and asserts three foundational design principles:
The term "genre" is not used very often in the UI design field. It is more associated with media and digital games. However, this term might be useful even in the context of business applications. There, we speak of "transactional applications", "light-weight applications", "consumer applications", "mobile applications", and so on. The term "genre" might help make it easier to refer to these "application types."
The humanistic perspective of Murray's design framework comprises:
In short, we can identify the following two main points in Murray's humanistic design perspective and for her design framework:
The main insight of Murray's book is "that everything made of bits is part of the same digital medium, because it shares the substructure of computation." The digital medium distinguishes itself from traditional media such as film and print by offering "a unique combination of properties", or "its own unique affordances", that can be used for symbolic communication." She explains that "by understanding the affordances of the digital medium – its procedural, participatory, encyclopedic, and spatial properties – we can exploit them appropriately to develop more coherent media conventions, the digital formats and genres that will expand the scope of human expression."
Thus, in Murray's framework, the four affordances of the digital medium open up the above-mentioned "wider view of design possibilities" (or "expanded design/decision space") and provide "the context for all of our design choices." I already mentioned the two goals in approaching design as a cultural practice. Now I can complete Murray's original statement by explaining how these goals can be achieved: by "refining or creating conventions that best exploit these four affordances." (The complete citation is as follows: "In approaching interaction design as a cultural practice our aim is always to make an object that is satisfying in itself and that advances the digital medium by refining or creating conventions that best exploit these four affordances.")
I have to admit that I am unfamiliar with Murray's use of the term "affordance." For example, she speaks of the "procedural affordance" of the digital medium when she refers to procedural properties in general; she also uses the term "property" in lieu of "affordance". I am more familiar with Don Norman's more general use of the term. (But note: He currently prefers the term "signifier" to "affordance".) Therefore, I tend to translate the term "affordance" internally to "design dimension" (which I think is closer to Murray's occasional use of the term "property"). Note that Murray also speaks of "representational affordances" when looking at the computer as a single new "medium of representation."
Murray relates each of the affordances to one primary "field of study" or "most important contributory discipline." Designers "can draw on this discipline to maximize the expressive potential of digital artifacts and of the larger digital medium." That is, viewing the computer as a specific medium makes use of concepts and convention from these disciplines. Definitions of many of the concepts can be found in the glossary at the end of Murray's book.
Table 1 below lists the four affordances of the digital medium, their definitions (from the glossary), as well as the primary related disciplines or fields of study, as Murray calls them:
| Affordance | Definition | Most Important Discipline |
| Procedural | The ability to represent and execute conditional behavior (computer vs. earlier media) / the processing power of the computer that allows us to specify conditional, executable instructions. | Computer science |
| Participatory | The digital medium is participatory in allowing an interactor to manipulate, contribute to, and have an effect on digital content and computer processing. | Human-computer interaction (HCI) |
| Encyclopedic | The digital medium is encyclopedic in three ways: its capacity, its extensive range of legacy and computational media formats and genres, its ability to represent any symbolic representation (including simulations of highly complex systems). | Information science |
| Spatial | Digital environments can represent space using all the strategies of traditional media, such as maps, images, video tracking, and three-dimensional models. Unlike older media, digital media artifacts can be navigated. | Visual design (Visualization) |
Table 1: The four affordances of the digital medium, their definitions (from the book's glossary), and the most important disciplines from which to use concepts and conventions
For Murray, the procedural affordance is the most important affordance because it is "the processing power of the computer that allows us to specify conditional, executable instructions" and thus to realize digital media.
Murray explains that interactivity results from combining the procedural with the participatory affordance. But for her, interactivity is not a design goal in itself – agency and immersion are the real design goals. She states that when both affordances fit together well, that is, when visible procedurality is combined with transparent participation, this creates the satisfying experience of agency (that is, makes something happen in a dynamically responsive world).
I try to combine other affordances below.
According to Murray, "these four properties constitute our design space the context for all of our design choices. Individual projects will be located at various points in that design space, exploiting one property more than another. But thinking of the potential for any project to more fully exploit each of the four properties can help us to discover new directions that we may have previously overlooked." Murray also describes this approach as "a framework for innovative thinking based on examining individual projects within a grid of possibilities."
Murray formulated the principle of "maximizing the affordances of the medium" as follows: "One way of thinking about advancing the medium is to aim at maximizing all of its affordances." However, this does not mean that every possible application of digital technology should be included, but "designers should imagine the many ways in which each of these affordances can be applied to the design task. To support this task, she visualizes the resulting design space in the form of a grid. "We can think of the four affordances as a grid, offering conventions and genres that have become sufficiently standardized to be adopted across projects and platforms." For example, single artifacts can be entered into the grid to visualize to what extent they exploit the different affordances, or examples of standard formats or genres can be arranged around the grid to visualize which affordance they primarily exploit. Table 2 below shows the four affordances of the digital medium with filled-in examples of standard formats and genres that exploit each of them:
Information Spaces
S p a t i a l |
Databases
Encyclopedic |
Procedural
Game Engines |
Participatory
Blogs & Instant Messaging |
Table 2: The four affordances of the digital medium with examples of standard formats and genres that exploit each of them (after Murray)
Murray proposes to use the grid of affordances as an aid in designing and analyzing digital artifacts:
Figure 1 below presents two examples of affordance mapping: the early Google search site focusing on the procedural and encyclopedic affordances, and the flickr photo sharing site focusing on the participatory affordance.
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Figure 1: Two examples affordance mapping using the grid of affordances (after Murray)
Personally, I have difficulties with mapping applications to the affordance grid, probably because I am a physicist and used to exact scales. I have to admit that he arrangement of the four spaces with its horizontal and vertical center lines reminds me of the typical schema of a four-quadrants diagram, which is based on numerical scales.
Murray's grid inspired me to look for different styles of visualizing the design space and to think about how affordances other than the procedural and participatory ones might combine together. Figure 2 below shows my slightly modified version of the flickr mapping, which led me to propose calling the combination of the participatory and the encyclopedic affordances "social" and to suggest the social web as a related field of study for the combination:

Figure 2: Affordance mapping using a modified grid of affordances
Furthermore, I propose to call the combination of the spatial and the encyclopedic affordances "abstract spatial", and relate this combination to the field of information visualization (Murray handles this within the spatial affordance). I am also a little bit unhappy with the assignment of visual design to the spatial affordance – at least, I have a different understanding of the term "visual design." I therefore suggest using the term "visualization". Note that I propose to assign the combination of the procedural and participatory affordances to the field of interaction design.
Admittedly, I have no idea what combining the procedural and the spatial affordance would mean ("intelligent" maps?). There are two more combinations of affordances possible, but they are harder to visualize in Murray's and my version of the grid: procedural combined with encyclopedic (hypertext?), and participatory combined with spatial (adventure games?).
Finally, I would like to point out that Murray's visualization seems very appropriate for the purposes she proposes for the grid, particularly because the squares make it easy to enter text (see Table 2 for illustration).
I was tempted to investigate, whether four is the correct number of affordances and whether the affordances and labels Murray chose are the right ones, but – not very surprisingly – I was not able to come up quickly with a viable alternative proposal. After all, Murray describes her framework as a design practice, not as a taxonomy or research approach. Top priority in a design practice is that its elements are useful in the designers' daily work; an overlap or arbitrariness in the terms it uses is not so important.
To sum up, the framework Murray outlines in her book Inventing the Medium, is based on the digital medium and its four affordances – in other words, its procedural, participatory, encyclopedic, and spatial properties. The common design vocabulary and conventions are provided by the contributing disciplines computer science, visualization, information science, and human-computer interaction. Finally, assembling the affordances in a grid provides a design space and a method for exploiting and maximizing the affordances of digital artifacts.
For more information about Murray's framework, read my review (in progress) of the book and the book itself.