Metaphor in User Interface Design

CSE 595 -- Winter 1997

Outside of the computer domain, we usually think of metaphors as being restricted to poetry and flowery writing. Within the computer domain, for user interfaces the desktop metaphor is well-known, and other kinds of graphical user interfaces are often consciously designed with a metaphor in mind (see e.g. Thomas Erickson's paper "Working with Interface Metaphors").

However, we don't usually talk about other kinds of interfaces, e.g. textual ones, as being constructed based on a conscious metaphor, nor do we often talk about the metaphors behind other aspects of computers.

Lakoff and Johnson argue (convincingly to me) that metaphors are not just restricted to poetry, flowery writing, and Macintoshes, but an essential part of everyday speech, and indeed our conceptual system. Particularly if they are correct, the study of metaphor becomes an essential part of studying human-computer interaction.

"Metaphors We Live By" by Lakoff and Johnson

The essence of metaphor is understanding and experiencing one kind of thing in terms of another.
Lakoff and Johnson argue (convincingly to me) that metaphors are an essential part of everyday speech. They further argue (based primarily on linguistic evidence) that most of our ordinary conceptual system is metaphorical in nature. Examples: "argument is war", "time is money".

Metaphorical Systemacity: everyday metaphors are used pervasively and systematically.

Examples:

The CONDUIT Metaphor

Ideas (or meanings) are objects.
Linguistic expressions are containers.
Communication is sending.

Orientational Metaphors

Ontological Metaphors

(ontology: "the branch of metaphysics dealing with the nature of being")

entity and substance metaphors; container metaphors

Personification

example: inflation as a person

Metonymy

Metonymy: using one entity to refer to another that is related to it.

Challenges to Coherence of Metaphor

Example: time as a moving object ... apparent contradiction in our metaphor for time.

"In the weeks ahead of us ..." (future is in front of us)
"In the following weeks ..." (future is behind us)

However, in the first example, time is moving toward us; in the second, the weeks that follow are following the current week.

Another example: love as a journey ... different kinds of journeys (car trip, train trip, sea trip). Here, there are various metaphors for love, but they are all coherent.

coherence vs. consistency: compare "argument is a journey" with "argument is a container"

Partial Nature of Metaphorical Structuring

The metaphorical structuring of concepts is necessarily partial. What about the "unused" part of a metaphor, e.g. "theories are buildings"?

How is Our Conceptual System Grounded?

Are there any concepts that can be understood directly, without metaphor? If not, how can we understand anything at all?

prime candidates: simple spatial concepts, such as "up", that arise out of our direct experience as beings with bodies in the world.

Causation

directly emergent concepts (e.g. up-down, in-out, object, substance); emergent metaphorical concepts (an activity is a container)

causation: directly emergent core that is elaborated metaphorically

direct manipulation: the prototype of causation. Piaget hypothesized that infants learn about causation by realizing they can directly manipulate objects around them.

metaphorical extensions of prototypical causation:

Connecting Lakoff and Johnson with User Interfaces

First, note that all UI's have a metaphorical basis, whether this was part of the designer's conscious thought or not. Example: unix.

computer examples of Lakoff & Johnson's metaphor lists:

Importance of direct manipulation user interfaces -- they tap into early childhood experience and prototypical causation. See point on Alan Kay tape of tapping into kinaesthetic sense (as well as visual and symbolic reasoning).

An Aside: grumble about violent metaphors in computer science

kill a process, abort a process, hit a button, use divide and conquer algorithms ...
quite satisfactory other metaphors are available: quit a process, interrupt a process, press a button, ...

Actually, this is an instance of a more general problem in science and engineering: attacking a problem (problem is an enemy), etc. (See e.g. feminist critiques of science.) Some members of the HCI community has been quite clear about pointing out the problem in user interfaces though.

Metaphor in the Alternate Reality Kit

The Alternate Reality Kit was a system constructed by Randy Smith at Xerox PARC in the 80's. It has a very strong physical system metaphor. All objects have position and velocity, for example.

Smith notes that there can be a tension between literally following a physical metaphor, and ease of use, functionality, and performance. He proposes a literalism-magic distinction.

Examples from his paper:

Generalizing: it seems that people usually don't have much trouble with extending a metaphor, mixing metaphors, or (to a lesser extent) moving way beyond a metaphor. (Compare this with the notion of "coherence" in Lakoff & Johnson.) They really don't like things that fall within the metaphor and contradict it. (L&J call this "consistency" or "lack of consistency".)

Also see Jonathan's work on consistency in user interfaces: J. Grudin, "The case against User Interface Consistency," CACM 32(10), p 1164-1173.

Examples from the desktop metaphor:

Metaphorical coherence in the desktop metaphor:

actually there are several different metaphors (I think):

Window metaphor: a (computer) window is a window (on a building or vehicle). The window lets us see into part of the computer (computer as container). We can move the contents in the computer around (scrolling), or we can move the window. (When we move the window on the screen, why doesn't the contents change?)

Metaphors for Computation

some Alan Kay metaphors:

Thomas Erikson, "Working with User Interface Metaphors"

The interface to a program will have metaphors, whether we design it that way or not.

Importance of a good metaphor -- voicemail example.

Coming up with user interface metaphors

Change and evolution (Bruce Tognazzini)

  1. Consistent interpretation of user behavior by the system is more important than consistent system objects or behaviors (compare with Norman's discussion of error)
  2. If you must make a change, make it a large and obvious one.
Consequence: you can change the entire look and feel of an application as long as you honor the user's previously learned interpretations and subconscious behaviors.

Metaphors for the World Wide Web

Example to be used in class discussions: