Cognition: Memory, Attention, and Learning - Foundations for Designing User-Centered Systems - page 131

they use, their home page, or where they put a manual on a bookshelf may all
become part of their knowledge about how to use a system because these aspects
can influence the retrieval of items from memory. This also suggests that, for more
robust recall of items from memory, users should be supported in building up a
variety of retrieval cues and have a chance to practice (i.e., rehearse) these items in
a variety of situations before they have to retrieve them in earnest.

5.2.4.4 Priming

Priming refers to how presenting objects before their use, sometimes quite briefly,
facilitates their use and the use of items related to them. Typically, primes are
presented for short periods of time, under a second, but it applies to all time
periods. For example, anything about Nepal or South America would be more
recognized by readers of this text because they have been used previously.
This approach can be used to facilitate the retrieval of items from memory.
When presented with a list of words to remember, such as ''bed rest awake tired
dream wake snooze blanket doze slumber snore nap peace yawn drowsy,'' many
subjects will report that ''sleep'' was included as well. This effect can be explained
by noting that many, if not all, of these words prime the word ''sleep.'' When it is
time to recall the words, the word ''sleep'' is also very active, and this is (falsely)
used as a cue that it appeared in the list as well. The topic by Intons-Peterson and
Best ( 1998 ) explores this and related topics of distortions in memory.
Users will find it easier to retrieve items from memory that have been recently
used. This is a possible mechanism to explain why consistency within a system or
between a manual and a system is important. Names of items in the manual will be
more quickly identified in the interface if the same name is used. Related concepts
will also be helped, but to a lesser extent.
This effect also can lead to retrieving information to support previously held
beliefs, rather than generating new ones. It is important then to provide users with
external memory aids to help in the retention and analyses of situations.

5.2.4.5 The Loftus Effect

The Loftus effect (e.g., Loftus 1975 ), also known as the misinformation effect,
describes how people take on knowledge implicitly from questions. Asking
someone a question often leads them to assume and later learn the facts implicit in
the question. Asking someone ''What color hat was the suspect wearing?'' will
lead many people to infer and later recall (without understanding that they just
inferred and did not see) that the suspect was indeed wearing a hat. In one of their
original studies Loftus and her colleagues asked subjects if they recalled meeting
Bugs Bunny at Disney World as a child (Loftus 2003 ). Depending on the condi-
tion, about a third could erroneously recall this (Bugs is with Warner Brothers, not
Disney!). Instructions and manuals can suggest capabilities not generally