CEN3722 Human Computer Interaction Attention and Memory Dr. Ron Eaglin

Objectives Understand the implications of attention for design Focus and divided attention Automating processing Chunking Limitations of human memory

Attention Design should help users find information they need Structure interface – easy to navigate Correct amount of information Use groupings Use correct ordering

Attention Focused Attention – Attend to one item at the exclusion of competing stimuli Divided Attention – Attend to more than one stimuli at a time These affect the how well we interact with a system

Attention Users will be distracted Suspended activities Cognitive Aids Users forget where they left off Forget if task was completed Cognitive Aids Reminders of status of activity – status bar Reminder of completion of activity – reminder of completion

Attention Use Spatial Cues Use Temporal Cues

Spatial Cues Name Address Phone # Jane Done 423 J St. 555-1234 Example A: Example B: Name Address Phone # Jane Done 423 J St. 555-1234 Yu Chen 874 Smith St. 555-4321 Kay McBride 848 Jones St. 555-9876 John Smith 123 A St. 555-1111 Jane Done 423 J St. 555-1234 Yu Chen 874 Smith St. 555-4321 Kay McBride 848 Jones St. 555-9876 John Smith 123 A St. 555-1111

Temporal Cues Complete Homework 1 Overdue Complete Homework 2 Task Deadline Complete Homework 1 Overdue Complete Homework 2 Due Friday Complete Homework 3 Due Next Friday Take Quiz 1 Due in 2 Weeks

Attention Flashing or Movement Warning !! Audio Warnings

Attention-Urgent Simple message Requires user response Information Needing Immediate Attention Requires user response

Attention – Informational Status information – status bar at top or bottom of screen. Use consistency in area of the screen where status is displayed.

Attention – Help and Assistance Available upon request – but easy to find and consistent

Automatic Processing Overlearned Activities Activities that have become automated Listening Reading Walking We do not consciously think about these activities

Automatic Processing More practice leads to improved performance – we become skilled and eventually performance is automatic Characteristics Fast Demands minimal attention Does not interfere with other activities Unavailable to consciousness

Experiment – Say Colors Out Loud Which one does it take more focus to State colors? Automatic processes (reading) conflict with process of perceiving color. Stroop Effect

Multi-Store Memory Model Input or stimuli Sensory store Loss from sensory store Select and actively process Working Memory Loss from short-term memory store Long-term Memory Decay, interference, loss of strength in long-term memory store

Working Memory Most people can hold 7 “chunks” of information in working memory Chunk = number, item, word Magical Number 7 + or – 2 Chunks depend on person, experience, context Chunking means meaningfullness

Memorize – (3 sconds) 3002200210020002

Memorize (3 Seconds) 3002 2002 1002 0002

Chunking Same number – different chunking (16 bits vs. 4 bits vs. 1 bit (pattern)

Memorize you welcome we today kindly sir thank how fine are

Memorize Welcome, how are you today? Fine, we thank you kindly!

Memorization – Different number of chunks you welcome we today kindly sir thank how fine are

Recognition vs. Recall Make things visible, making recognition easier We can recognize material far more easily than we can recall it from memory Obvious implications for interface design: Make things visible, making recognition easier Compare: menus vs. command line Recognition: knowledge in the world Recall: knowledge in the head

Familiarity – Words and meaning He has a predilection towards autonomous artistic creation He likes to create things on his own

UI Design Items that need to be remembered at the interface should be as meaningful as possible Problems with command line interfaces e.g., command names and icons should be selected according to meaningfulness cp vs. copy rm vs. remove cat, grep, lint, mv, pr, lpr (huh?)

UI Design

Summary Design interfaces to help users find information/perform tasks Use cues (grouping, color, sound, icons, familiar words) Understand focused vs. divided attention Understand automatic processing Understand limitations of human memory Understand Chunking Recognition vs. recall