Deep Thinking
Problems Before Patterns: A Different Look at Christopher Alexander and Pattern Languages
Molly Wright Steenson Princeton University School of Architecture | [email protected]
Interaction and system design- tions, explored by Aaron Marcus, While pattern literature often ers alike gravitate to the idea of Shelley Evenson, Hugh Dubberly, focuses on patterns, there’s [1] Alexander, C., S. Ishikawa, and M. pattern languages. The notion and Rick Robinson, to name a an even greater focus on the Silverstein. A Pattern of patterns comes from the few [2,3]. Alan Cooper’s approach reproducible solution to a design Language: Towns, Buildings, Construction. work of architect Christopher to design was strongly inspired problem. As patterns move to New York: Oxford Alexander, who with his associ- by pattern languages. Kent Beck online reference models, they University Press, 1977. ates Sara Ishikawa and Murray and Ward Cunningham not only concentrate less on outlining the
[2] Aaron, M. “Patterns Silverstein of the Center for cite Alexander’s influence on the problem and the context, and Within Patterns.” interac- Environmental Structure, pub- development of object-oriented more on the object, component, tions 11, no. 2 (2004): 28-34. lished A Pattern Language in 1977. programming languages at or interface solution. Where The book defines a set of funda- Xerox PARC in the early 1990s, this might help someone find a [3] Dubberly, H., mentals for building and plan- but also on extreme program- quick reference, it can be done S. Evenson, and R. Robinson.” The ning urban and architectural ming during the later part of the at the detriment of a problem Analysis-Synthesis projects that can be used by decade [4, 5]. And Erin Malone statement that offers expertise Bridge Model.” interac- tions 15 no. 2 (2008): non-expert designers. “Each pat- and Christian Crumlish are and context. John Vlissides, one 57-61. tern describes a problem which currently writing a book about of the four authors of Design occurs over and over again patterns for social software, Patterns: Elements of Reusable [4] Beck, K. “Embracing Change with Extreme in our environment,” wrote titled Designing Social Interfaces: Object-Oriented Software, noted Programming.” Alexander and his coauthors, Principles, Patterns, and Practices for in a 1997 article that one of the Computer 32, no. 10 (1999): 70-77. “and then describes the core of Improving the User Experience. primary offerings of patterns the solution to that problem, For designers of many disci- as a whole is their usefulness [5] Beck, Kent.
March + April 2009 (1997): 30-33. com/designpatterns/ pubs/top10misc.html.> interaction and software design- thought that patterns should Alexander and his colleagues Accessed 24 November 2008 ers. Pattern languages have be shared via an ever-growing, defined the landscape of the made numerous appearances open database of design prob- design problem in 1967—a Photograph of Christopher Alexander by Richard Morgenstein interactions in previous issues of interac- lems and solutions [6]. decade earlier than the publi- 20 Deep Thinking cation of the more familiar A these requirements, Alexander the problem, as it exists today Pattern Language. The methodol- expanded the architectural [6].” The pattern, then, is a set of ogy in the manual specifies a notion of program (it specifi- parts that relate to each other structure for setting up design cally means the set of functions in space. Patterns can address problems in order to find gen- fulfilled by a room, space, or anything from the appropriate eralities, particularities, and building). It is a program, he layout for a kitchen, to freeway eventual solutions. The authors wrote, “because it provides ramps, to designs for users of a considered it a “minimal and directions or instructions to the certain income or educational natural” format: the what, designer [8].” If this sounds like level, to furniture design, to where, and how of a situation; engineering language, it is no structures that hold up houses in other words, the problem, surprise. Alexander developed [6]. Where they can address a the context, and the resulting design-requirement data sets in huge variety of problems, they pattern [6]. Shifting the focus the early 1960s that were com- themselves seek to be reductive to the definition of the design plex enough to necessitate an and essential, offering only what problem and not just its result- IBM 704 mainframe computer is necessary. Where patterns ing pattern helps to ensure the for analysis. With his colleagues might not provide the only solu- pattern properly addresses the at the Center for Environmental tion to the problem, without it or situation, particularly in com- Structure, Alexander moved an equivalent, “the problem will plex environments. away from such a byzantine go unsolved [6].” Alexander long maintained analysis of requirements, instead Although titled the Pattern an interest in defining a design seeking a method for creating Manual, its heart is the design methodology in the face of com- straightforward descriptions of problem statement—the most plexity. Notes on the Synthesis of the program—that is, the design important element “from a Form, originally published in problem—in the Pattern Manual. human standpoint [6].” Problems [8] Alexander, C. Notes 1964, more than 20 years before The manual defines a gram- subsume the considerations on the Synthesis of Form. Cambridge, MA: A Pattern Language, outlines matical structure that maps that system designers address, Harvard University Press, 1971. the difficulty of designing for to a designer’s mental model. called “functional demands… a series of intermeshing, inter- A designer follows three steps [that] at one time or another acting systems, even when the when developing a pattern, “or, [have] been called requirements, final designed object itself might for that matter, [when he] enter- needs, performance standards, not look complicated. “In spite tains any idea about the physical facts, tendencies, objectives, of their superficial simplicity,” environment…. He considers a constraints, activities, technical Alexander wrote, “even these problem, invents a pattern to data, and so forth.” Yet the func- problems have a background of solve the problem, and makes tional demands do not stop with needs and activities which is a mental note of the range of what a system should do: They becoming too complex to grasp contexts where the pattern will address a wide variety of issues intuitively;” needs and activi- solve the problem [6].” Contexts surrounding the ecology of a sys- ties that sit within a growing and problems are paired with tem. “They may concern human ecosystem of other pressures, each other—wherever a par- behavior, economics, the state whether social, cultural, or ticular context appears, so too of technology, the political cli- informational [8]. In this setting, does its problem. The context mate, whatever. No limits can be Alexander found no place for modifies the pattern in the way placed on the kinds of elements the secret, intuitive processes that an adverb modifies a verb: necessary to describe a problem traditionally claimed by many It says how the pattern works properly [6].” designers, ones which did not and in which circumstances it If that sounds vast, it is. March + April 2009 take the intricacies of their con- is valid. The problem statement Patterns address an astonish- texts into consideration. Instead, provides the reasoning behind ingly wide variety of elements he advocated a logical, objective the pattern and context. It can that are organized in space in approach to design, in which be much lengthier, offering an some manner. The Pattern Manual form fit context by addressing a explanation of the situation, a offers an expansive list that interactions set of design requirements. With “common-sense description of includes “all kitchens; dormitory 22 FEATURE kitchens; efficiency apartment r*GUIFIPVTFJTPOFPGBSFHV- ations, Alexander, Ishikawa, and kitchens; …all industrial sites lar sequence of houses all using Silverstein all anticipated and larger than two acres; a 2x4… this pattern, then the sign letters inspired contemporary methods residential areas with 40 percent are at least 6 inches high. for design thinking. By seek- of their population under 25 r*GUIFIPVTFJTJTPMBUFE PS ing to provide “a natural way and median incomes between is one of a regular sequence of of expressing thoughts about $6,000 and $8,000; garden paths; houses not using this pattern, the physical environment,” the cobblestone paths; a doorknob; then the sign letters are at least authors offered a vital means any freeway; freeway exit ramps; 12 inches high [6]. to articulate the richness not bookshelves [6].” Any of these Consequently, a simple pat- only of a design solution, but its patterns provides a solution to tern that addresses angle and problem and its context [6]. At a problem that exists in space, direction of signage and the the same time, the earlier pub- whether the demographics of size of letters tackles a broader lication of Pattern Manual serves a neighborhood, the kind of design problem. It notes different as a reminder for elements of structure required for a house, a use cases—sequences of similar patterns that often receive less transportation issue, or the opti- houses versus isolated or nonse- focus. At the heart of every pat- mal setup of a dormitory. quenced houses—and offers dif- tern is a design problem. When As an example, the Pattern ferent variables for the solutions. well defined, the design problem Manual describes the difficulty While a designer could simply represents the designer’s collec- of reading house numbers from use the pattern, the richness of tive expertise of issues, infor- a moving vehicle. It states the the framework lies in the overall mation, and problem context, context tersely and specifically: problem statement and context. making for better patterns and “Freestanding house on a street Furthermore, the goal of pat- design solutions. In examining where cars move at speeds tern libraries is not only to offer how the pattern language devel- [9] Alexander, C. between 5 miles per hour and 30 solutions to design problems, oped, we see how important Theory, Organization, Activities. [Pamphlet], miles per hour [6].” The problem but also to solicit critique and the latter parts of that sentence Berkeley, Center statement is much longer—in invite improvement. “We want were to Alexander and his col- for Environmental Structure, 1968. this case, three pages—and sets our ideas to improve under pub- leagues—and to the continued out the series of issues the pat- lic scrutiny,” wrote Alexander’s evolution of design thinking in tern will need to address, begin- team, “and we want our good general. With straightforward ning with: “House numbers are ideas to be potentially com- language, the problem and pat- very hard to see from moving bined with other good ideas [6].” tern language continue to bring cars, especially for the driver. The Center for Environmental a systematic approach to design Many signs are parallel to the Structure first sought to publish to the wider audience who prac- road (on the house face, or gar- its patterns under the rubric of ticed it, improved upon its ele- den gate), so that they can’t be a catalog to which anyone could ments, and continue to develop seen from up the street [6].” The submit patterns using the for- the concept today. rest of the problem statement mat described in this article. An includes facts about house num- editorial board would select pat- ABOUT THE AUTHOR Molly Wright bers and signage, references to terns; catalog subscribers would Steenson is a design studies on driver vision, and the receive the patterns. Alexander researcher and architectur- limits of potential positioning of and his colleagues thought that al historian who studies signs—in essence, the evidence by 1970, patterns could be stored interactivity and respon- siveness in architecture and urbanism. She for a case to support the prob- in a computer and offered to is a Ph.D. candidate in architecture at lem. The following pattern, for subscribers—a central feature to Princeton University and contributing editor for interactions. Steenson also conducts instance, addresses the house- contemporary pattern libraries March + April 2009 number problem: for games, object-oriented pro- research and develops design strategy for mobile, Web, and urban projects and blogs at r5XPIPVTFTJHOT FBDIBU gramming, or Web design [9]. Active Social Plastic (activesocialplastic.com). about 45 degrees to the street, Through their straightforward facing up and down the street, approach to describing a com- DOI: 10.1145/1487632.1487637 respectively. plex network of design consider- © 2009 ACM 1072-5220/09/0300 $5.00 interactions 23