- user competence targets the user’s capacity to interact with computers; the
design must take into account the visitor’s learning capacity. The navigation
results must be predictable, understandable even by a novice, facilitate
learning, and allow the transfer of new acquisitions to other situations; - robustness refers to the system not blocking on incorrect use, while signalling
and correcting the error.
Many potential problems of an information system can be identified through testing on a
small number of users. Nielsen (apud Mjornheden, 2004) believes 85% of troubles can be
uncovered by a user test on merely five persons.
The increase of computer system use is the object of HCI – Computer-Human
Interaction. The aim of the research is adapting technology to user needs, by
understanding the human limitations and conditions. Thus, designing an interface cannot
do without knowledge of how human sight, memory, and thinking operate (Berndtsson
and Ottersten, 2002, apud Mjornheden, 2004).
Laws Implications for design
Visual- sight and perception are partially controlled
by experience and interest- eliminating all unessential elements
- information presented on a screen is easier
to read and identify if the eye can follow a
row - normally, reading a text is 20-30% slower
on the screen than on paper- creating texts and links that should help a
client read fast and identify relevant content - clear description of the links
- using large font and avoid italics for links
- coherent and systematic presentation of
information
Memory
- creating texts and links that should help a
- short-term memory is very limited and
operates with a small number of
information units - it is much easier to recognize information
than remember it - long-term memory uses associations to
evoke things that provide users with a list
of eligible options- concise presentation without useless details
- adapting the vocabulary to clients’
specificity - anchor ideas facilitating the understanding
of new information
Thinking- thinking depends on other mental functions
(emotions, interests, etc.) - handling information is sequential and
thought cannot operate with too much
information simultaneously - people excel in information assessment and
problem systematisation according to
categories- full use of users’ knowledge
- creating homogeneous interface: the same
concept must look the same everywhere - users must be helped finding a pattern or a
structure for the way the system works - stimulating exploratory capacity facilitates
learning - relevant feedback to understand the
interface