the interaction The Interaction interaction models translations - - PDF document
chapter 3 the interaction The Interaction interaction models translations between user and system ergonomics physical characteristics of interaction interaction styles the nature of user/ system dialog context
– the area of work under study e.g. graphic design
– what you want to achieve e.g. create a solid red triangle
– how you go about doing it – ultim ately in term s of operations or actions e.g. … select fill tool, click over triangle
– traditional interaction … – use of term s differs a lot especially task/ goal !!!
– user establishes the goal – form ulates intention – specifies actions at interface – executes action – perceives system state – interprets system state – evaluates system state with respect to goal
user’s form ulation of actions
user’s expectation of changed system state
Fixing things? slip – better interface design m istake – better understanding of system
extension of Norm an… their interaction fram ework has 4 parts – user – input – system – output each has its own unique language interaction translation between languages problem s in interaction = problem s in translation
core
task
input
user intentions translated into actions at the interface translated into alterations of system state reflected in the output display interpreted by the user
– not restricted to electronic com puter system s – identifies all m ajor com ponents involved in interaction – allows com parative assessm ent of system s – an abstraction
e.g. controls grouped according to function or frequency of use, or sequentially
e.g. seating arrangem ents adaptable to cope with all sizes of user
e.g. physical position, environm ental conditions (tem perature, hum idity), lighting, noise,
e.g. use of red for warning, green for okay, awareness of colour-blindness etc.
– traditional … dials and knobs – now … screens and keypads
+ cheaper, m ore flexible, m ultiple representations, precise values – not physically located, loss of context, com plex interfaces
Vessel B Temp 100 200
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multiple representations
– user interacts with artificial world
– user interacts with real world through interface
– feedback – delays system interface plant
immediat e feedbac k instruments
– function keys, single characters, short abbreviations, whole words, or a com bination
– less recall - easier to use – rely on recognition so nam es should be m eaningful
– num bers, letters, arrow keys, m ouse – com bination (e.g. m ouse plus accelerators)
– sensible grouping is needed
– vague – am biguous – hard to do well!
– try to understand a subset – pick on key words
– user led through interaction via series of questions – suitable for novice users but restricted functionality – often used in inform ation system s
– used to retrieve inform ation from database – requires understanding of database structure and language syntax, hence requires som e expertise
– good design – obvious correction facilities
e.g. sum of all cells in this colum n
…
– highlighting – visual affordance – indiscrim inate use just confusing!
– use for extra virtual space – light and occlusion give depth – distance effects flat buttons … …
also see supplementary material
– can contain text or graphics – can be m oved or resized – can overlap and obscure each other, or can be laid
– allow the user to m ove the contents of the window up and down or from side to side
– describe the nam e of the window
– WIMP style relies on pointing and selecting things
problem – take a lot of screen space solution – pop-up: m enu appears when needed
File Edit Options Typewriter Screen Times Font
– pull-down m enu - m ouse hold and drag down m enu – drop-down m enu - m ouse click reveals m enu – fall-down m enus - m ouse just m oves over bar!
– pop-up m enus - actions for selected object – pie m enus - arranged in a circle
… but not widely used!
– hierarchical m enu structure – m enu selection opens new m enu – and so in ad infinitum
– key com binations - sam e effect as m enu item – two kinds
usually different !!!
– shown/ hidden via m enu option e.g. available shapes in drawing package
– m enu ‘tears off’ to becom e palette
“ you want a ticket from New York to Boston?”
windows, icons., menus, pointers, buttons, etc.
e.g. MacOS vs Windows m enus
– com e and won’t go away! – good for errors, essential steps – but use with care
hello, this is the Go Faster booking system what would you like? (user) I want to fly from New York to London you want a ticket from New York to Boston (user) no sorry, please confirm one at a time do you want to fly from New York (user) yes … … …
– desire to im press, com petition, fear of failure
– fear, allegiance, am bition, self-satisfaction
– cause frustration and lack of m otivation
– not enough that people can use a system – they must want to use it!
– flow (Csikszentimihalyi) – balance between anxiety and boredom
– zone of proximal development – things you can just do with help
– literary analysis, film studies, drama
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within categories: e.g. safety – cooker controls front panel – safer for adult rear panel – safer for child between categories e.g. ergonom ics vs. physical – MiniDisc rem ote ergonomics – controls need to be bigger physical – no room! solution – multifunction controls & reduced functionality
e.g. on/ off buttons
e.g. arrow buttons, twist controls
series of spring-back controls each cycle through some options –natural inverse back/ forward twist for track movement pull and twist for volume – spring back – natural inverse for twist
state evident in mechanical buttons rotary knobs reveal internal state and can be controlled by both user and machine
BUT NOTE
– chapter and page number
– full paragraph of context
individuals value organisational value