  

 1.How to account for system generated and environmental interruption and distraction of user 2.How to create the system so that it supports interruption and distraction of user 3.How to test systems while incorporating the interruptions common to its users

 Working on task Interruption Attention moves to new task Interruption & task completed Return to original task What was I doing again?? Time to re-orient yourself to the original task

  Zeigarnik Effect: Users who are unable to complete a task are more likely to remember it vs. the completed tasks

  Journal of Experimental Psychology article states: “ Demanding conditions as well as interruptions revealed rapid forgetting of intentions at levels that would be considered significant in applied settings.” “The results suggest that maintaining intentions over brief delays is not a trivial task for the human cognitive system “

Human attention is a limited resource Selective Attention: ability to concentrate on some things and ignore others Divided Attention: ability to divide attention among multiple tasks   WHERE is that threshold?

  Likely to cause the user memory loss Decreased decision accuracy Increased decision time for interrupted task

  Cognitive Load of Task Time to Re-Orient Time to Complete Task Error Rate

 All participants of previous study attended to interruption immediately Users intend to complete tasks with 100% accuracy Users will forget some part of the interrupted task without a cued recall Users anxiety and annoyance levels will increase as interruptions increase

  Driving + going through intersection ONLY: Glances at traffic light= Mean 1.70 Mean 2.68 Driving + TALKING on cell phone + going through intersection: Glances at traffic light=

  7.8% = the mean percentage of times drivers did not glance at traffic light 21.9% = the mean percentage of times drivers did not glance at traffic light while talking on the cell phone

 What is critical and what is peripheral? Contextual Inquiry is paramount Support the development of filters or agents

 Ambient information cues Sensory related notification Note: any background noise or movement distraction could cause user to ignore notification

 “CommuterNews”: A persuasive in-car entertainment and news service What was their testing methodology? Quote: “Most of the preliminary user tests did not occur in a driving situation”

 Other methods of driver notification: Pneumatic Tactile Alerting System Vibratory tactile means to alert driver of warnings Vary the pulses in duration, frequency, speed and driver will be able to discern what alert is for

 Investigate and develop a more thorough, systematic way of contextual inquiry How to determine what is truly important to users Proposed “Distraction Lab”

 Distraction Lab for Prototype testing (cont’d) Apply information gleaned from contextual inquiry to mimic interruptions found at user’s place of work Use timing and recording devices to determine re-orientation time Delve into user’s satisfaction/annoyance levels

  