Cognition: Human–Computer Communication - Foundations for Designing User-Centered Systems - page 199

Hand

Hand

Volume Pitch

Fig. 7.1 A diagram of a Theremin. Users play it by moving one hand closer to or farther away
from the volume control and the other hand closer to or farther away from the pitch control. The
distance is measured through capacitance. There are no fixed volumes or pitches, unlike most
other instruments. It is sometimes used to make eerie sounds in science fiction movies

Language relies on both syntax and semantics, as do interfaces. Syntax refers to
how words are organized to create meaning. The order in which objects are chosen
and the order of interaction are both questions of syntax. Is it better to select an
object (a noun) and then an action to apply to it (a verb)? Or is it better to select an
action and then the object? Some systems use the noun-verb syntax, whilst others
use the verb-noun syntax. The Macintosh OS has you select a file and then choose
to compress it or duplicate it. Eudora and Gmail, two commonly used email
interfaces, have you select that you wish to attach a file to an email, and then
choose the file.
Semantics refers to the meaning of words and symbols. How symbols are used in
an interface is a question of semantics. The choice of type of symbols to use in an
interface—usually words or icons—depends on their semantics. This is often a very
difficult choice to make. The meaning that users ascribe to a particular word or the
word that they first associate with an action is not uniform. Furnas et al. ( 1987 ), for
example, found that there was a wide variability in the words users choose when
asked to name actions: the users agreed on the same term for an action less than 20%
of the time. The results suggest that designers should not just use the first word they
think of, and that they should also support the use of aliases to help match the user's
terms. (See Glushko 2013 and Kernighan and Plauger 1978 for more concrete
suggestions.)

7.2.2 Grice's Maxims of Conversation

People routinely use language to converse and interact. Grice ( 1975 ) proposed that
the way that they interact with one another can be described by the co-operative
principle: