Multitasking Theorien?
Task switching
Interruption (Memory for Goals)
Multiple Tasks (Threaded Cognition)
Prospective Memory
Longer time frames of multiple tasks (STOM model)
Task switching?
UV: 2 discrete tasks that alternate (letter task, digit task)
AV = switching cost
Limitationen: Labor, nur Kognition, fehlende "real world implication”
Task switch = switch von letter zu digit task
Interruption Diagramm?
Interruption Phasen?
Distraction/attention request
Interruption lag
Interruption
Resumption lag
Interruption: Distraction/attention request
visual or auditory event that observably captured the attention of the participant and delivered some information
Interruption: Interruption lag?
time between alert and actual begin of secondary/interruption task
Interruption: Interruption?
time that secondary/interrupting task is attended (retention interval)
Interruption: Resumption lag?
time to resume primary task. Longer resumption lags indicate a more difficult resumption process, compared to shorter resumption lags
Memory for Goals Theory: Model?
Adaptive Control of Though-Rational (ACT-R) model to explain cognitive processes involved in deferral and resumption of task goals
goals are stored in long-term memory; goal with highest activation will be retrieved and directs behavior; goal activation decays over time
goal activation is elevated by:
strengthening (rehearsal)
priming (attention towards memory items or contexts that are associated with goal)
Memory for Goals Theory: Research Settings?
Memory for Goals Theory: Predictions and results?
longer interruptions lead to longer resumption lags
log function of decay; rapid rise of lag for interrupting length of 3-13s and asymptotic at 45s
more demanding interruption task resulted in longer resumption lags (due to less rehearsal during interruption)
forced interruption lags decrease the resumption lag (more/better encoding, higher goal activation weil mehr Zeit)
visibility of primary task during the interruption, audio interruption during a visual primary task and no context change during interruption decrease the resumption lag
Memory for Goals Theory: Limitations?
only one task
what constitutes a “single task goal”?
the primary task (that needs to be resumed) is always in central visual attention at the end of the interruption -> realistisch?
einzige AV: Resumption lag (-> no forgetting to resume task, almost no errors at task resumption?)
Fehler treten nicht auf
vor allem Laborstudien
Multitasking Continuum?
Unified Theory of Multitasking? (3 Parts/Theories)
Threaded cognition theory
Account for concurrent Multitasking performance for two or more tasks
ACT-R cognitive architecture
provides theory and computational framework
Memory for goals theory
account fo task interruption and resumption (sequential multitasking)
Threaded cognition theory?
task threads instead of goal activation
multiple active tasks (threads) to execute simultaneously across the ACT-R processing modules
threads are coordinated by procedural resource and executed by resource modalities
Threaded cognition theory: ACT-R cognitive architecture?
Threaded cognition theory: Assumptions for multiple tasks?
resource seriality assumption
threads can operate in parallel if they do not require the same processing (each module can serve only one task at a time)
greedy/polite polics
if a module is not in use, any of the threads can claim it (greed)
however, once a thread is done with a module, it releases it immediately (politeness)
Threaded cognition theory: sources of interference for multitasking?
the declarative module can lead to interference when two tasks both use memory for standard memory retrievals or for retrievals of task instructions
the problem representation module can lead to interference when two ore more tasks require complex representations that mus be swapped out for each task switch
the procedural module (= the central cognitive bottleneck of the system) can lead to interference when two tasks attempt to start using the same module at the same time
Threaded cognition theory: Memor for goals usage?
Threaded cognition theory: Predictions and results?
dual choice
pursuit tracking
driving and driving distraction
interruption and task resumption
uvm
Threaded cognition theory: Limitations?
the primary task (which needs to be resumed) is always in central visual attention at the end of the interruption
einzige AV: resumption times (no forgetting to resume task, almost no errors)
model requires detailed input
mainly lab studies
Prospective memory?
memory processes involved in remembering future tasks
resumption of interrupted task can be considered als prospective memory tasks
Encoding-Pausen, Encoding-Reminder, Retrieval-Pausen und Retrieval-Reminder verbessern Wiederaufnahmeanteil (s. Grafik)
Strategic Task Overload Management (STOM)?
computation multi-attribute decision model that predicts the decision aspect of sequential multitasking
overload situations where concurrent performance of tasks is impossible -> need to decide which task should I do?
what influences this decision?
STOM Komponenten?
Sensory properties of a task (Salience)
Effort of task switching (Effort): switch avoidance
Task priority (Value)
Task Interest
Difficulty of a task attribute
STOM Diagramm?
Nicht beachtete Aspekte von Multitasking?
Communication behavior
Artefakte (Assistive or everyday technology Handys zb)
planning and discretionary behavior
affective component
…
Fazit zu den Theorien?
detaillierte Models und viele empirische Studien verfügbar
die meisten Studien sind Laborstudien, wenig real life
viele mögliche Anwendungen / Anwendungspotenzial
ICU: Interruption management individual model?
support for Memory for Goals:
decay (length of interruption)
priming (context change)
does NOT support Memory for Goals:
factors that are based on rehearsal
nurses cann rehears, but did not actually rehears primary task
Predicting the effects of in-car interface: Aim?
dialing and driving: comparing different dialing methods and modeling the primary and secondary task performance
UVs:
dialing input (manual vs voice)
number of actions for dialing (speed vs full)
AVs:
time for dialing
driving performance
Predicting the effects of in-car interface: Varianten?
Predicting the effects of in-car interface: ACT-R modules?
declarative knowledge: individual units of factual knowledge (chunks)
procedural knowledge: process and skills for achieving a goal (set of rules that fire when conditions are satisfied)
perceptual modules
motor modules
Predicting the effects of in-car interface: Driving Model?
control of vehicle (lateral steering and longitudinal speed)
monitoring external environment
decision making
Predicting the effects of in-car interface: Dialing Model?
based on task analysis
standard elements of ACT-R
Predicting the effects of in-car interface: Integrated Model?
driving + dialing model (two subgoals)
if dialing is required, driving model cedes control to dialing model with p=0.5 after each control action
the dialing model returns control when a perceptual or motor action has been completed
Predicting the effects of in-car interface: Versuchsaufbau?
N = 11
Nissan based driving simulator
one lane
constant speed (~100kmh)
8*4 calls, 20s between calls
driving performance: during use + 5 seconds after
Predicting the effects of in-car interface: Results for dialing time?
Predicting the effects of in-car interface: Results for lateral deviation?
Predicting the effects of in-car interface: Results for lateral velocity?
Predicting the effects of in-car interface: Discussion of the prediction results?
the full-manual interface had large significant effects on driver performance, the speed-manual interface had small significant effects, and the voice interfaces had no significant effect
the speed-manual interface required the least-time, followed by the speed-voice interface, the full-manual interface and finally the full-voice interface
Predicting the effects of in-car interface: Limitations?
simulated and not real driving
single lane, no traffic, constant speed
keyboard simple and no feedback
model limitation: individual differences and learning not adressed (zB “dial by feel”)
Comparison Between HWD regarding RL: Aim?
Do different mobile information displays cause different effects on the resumption of the primary task?
AV = resumption lag
first study in laboratory setting
Comparison Between HWD regarding RL: Task and Conditions?
Comparison Between HWD regarding RL: UVs / Hypothesen?
UV1 Mobile Information Display
visibility/availability of primary task during interruption task reduces resumption lag
Tablet > Opaque HWD = HWD glance mode > HWD AR mode
UV2 Interruption Length
longer interruptions result in longer resumption lags
5s < 15s < 30s
Display x Length Interaction
no effect of length for HWD AR mode
Comparison Between HWD regarding RL: Results?
Interaction interval significantly shorter than resumption lag -> interruption was distracting
no main effect of UV1 (Mobile Information Display)
Main effect of UV2 (Interruption Length): 5s < 15s = 30s)
no interaction effect between UV1/UV2
Interruptibility of Software Developers: Aim?
to investigate the use of a combination of psycho-physiological sensors to automatically identify the interruptibility of a knowledge worker in a real-world working context
to investigate the correlation between interruptibility, mental load, and interruption lag (and resumption lag)
Interruptibility of Software Developers: Psycho-physiological sensors?
Electroencephalograph (EEG) and eye blink data
Electrodermal activity (EDA), skin temperature, blood volume pulse, interbeat interval, heart rate
Interruptibility of Software Developers: Method?
interruption on tablet
negotiated interruption (selbst entscheiden wann mans angeht)
one arithmetic task (1+2)
5-point Likert scale questions about disturbance, interruptibility and mental workload at time of distraction
Interruptibility of Software Developers: Studien?
Lab study
N = 10
60 min programming in Eclipse IDE
random interruptions
Field study (office of software company)
N = 9
120 min of regular office work
Interruptibility of Software Developers: Phasen?
Distraction: Tablet played sound, changed from black to white, start button visible
Resume Primary Task: Click on keyboard/mouse (lab: capture software, field: direct observation)
Edit lag: time from first click to first edit
Interruptibility of Software Developers: Results of classifications?
classifications: disturbance, interruptibility, mental workload
classification in interruptible vs. not interruptible:
Lab: 91.5%, Field: 78.6%
classification in five interruptible states:
Lab: 43.9%, Field: 32.5%
Interruptibility of Software Developers: Results of other measures?
interruption lag lab 30s and field 45s (!)
large positive correlations between perceived disturbance, interruptibility and workload (all r > .7)
significant correlation between interruptibility and interruption lag
lab r=0.382, field r=0.282
significant correlation between resumption lag and interruption lag in the field study, r=0.275 (schlecht für Theorie)
Interruptibility of Software Developers: Discussion / Limitations?
psycho-physiological sensors of automatic identification of interruptibility worked well in lab and field
Memory for Goals theory not well supported by results
Limitation: artificial interruption
Zuletzt geändertvor 2 Jahren