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Dr. Jill Drury, jldrury@gmail.com

n vers y o assac use s owe91.527 Intro to HCI

e ruary

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What well cover

r nc p es oethnography

Several types of task

analysis: Environment

Hierarchical

O erational se uence

Workload analysis

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Principles of ethnography

Use extended direct observation of the target culture tounderstand tacit behavior

o no s ar w ypo eses an use a sem -s ruc ureapproach

Observe how artifacts are used to accomplish real goals

Do not distort the meaning of the target cultureslanguage through a literal translation into the

Learn to speak the target cultures language

Do not have implicit assumptions that might biasnterpretat on, an test exp c t assumpt ons r gorous y

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Example: ATM

Goal: Obtain $100 in cash

Preconditions: Actor has card, knows PIN,has cash in account

Actor System

1a. Presents card

1b. Reads/validates account #1c. equests

2a. Enters PIN

2b. Indicates PIN entered

2c. Reads/validates PIN2d. Presents action choices

. .

. .

Postconditions: Actor has $100 in cash, System ensuresaccount balance is decremented by $100

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Use cases

xamp e: p oa ng g tplans to a UAV

Goal: Program the UAV to fly aparticular pattern

,

Actor System

1a.Enters command to set waypoint1b. Indicates readiness to accept waypoint

2a.Enters 1st waypoint

2b.Indicates 1st waypoint entry done

c. ea s va a es wapo n3a. Repeats 2a - c for other waypoints

4a. Enters command to upload waypoints

4 . n cates new g t pat s act ve

Postconditions: Aircraft will fly designated patternPhoto: Lou Nocca

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Well cover four types

or env ronment ana ys s

Hierarchical task analysis

diagrams

Workload diagrams

At Scripps Institute of Oceanography,

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researc ers eve ope a mouse t atcan be used under water

(photo courtesy of Scripps Institute)

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Work environment analysis

Typical office or not?

Noise?

Lighting?

Interruptions?

Describe socio-culturalenvironment

Draw implications forinterface design

ee pages - n

Mayhew for example

UPS drivers use a handheld computer

while standing and walking outside9

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Example work environment analysis: UAV SAR

Ph sical la out

Outside; could be cold No precipitation (a/c cant fly)

mosp ere

Tense, life and death situation

On your own, far from support

Socio-cultural environment

First responders are resourceful,,

Photo: Lou Nocca

Implications for interface design

Efficient to operate Prevents errors

Contains highly visible controls

Able to be worked using gloves 10

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Hierarchical task analysis

tart y ent y ng as c user tas s romobservation/interview materials

-

Identify the major steps needed to do the activity

In cases where there are alternative ways to do the task,

Keep decomposing steps until you get to the lowestlevel description that makes sense for your analysis

Refine by working directly with users

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Example: Borrow a library book (Sharp et al.)

access.

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Task anal sisExample: UAV Search-and-Rescue (SAR) MissionAssumes: batteries arechar ed, team is alread Scope: from after

UAV SAR (0)

at rescue site base,

frequency notification isposted, and equipment isun acked

equ pment was unpac e

at site but not assembled,through landing of aircraft

Prepare for mission (1.0) Execute mission (2.0)

PrepareEquip-

PrepareAircraft

PrepareMission Para-

LaunchAircraft

MonitorMission

LandAircraft

ment (1.1) (1.2) meters (1.3) (2.1) (2.2) (2.3)

Tasks based on my experience flying Procerus

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Task anal sisExample: UAV Search-and-Rescue (SAR) Mission

repare or m ss on .

PrepareEquip-

ment (1.1)

PrepareAircraft

(1.2)

PrepareMission Para-meters (1.3)

Turn On &Distribute

CableTogether

InsertZero

AttitudePitotTube

TrimAircraft

EnterWaypts

Insert a/c

Walkie-Talkies

(1.1.3)

Equipmt(1.1.2)

(1.1.1)(1.3.2)Test

(1.2.3)

(1.2.2) (1.3.1)(1.2.1)

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Task anal sisExample: UAV Search-and-Rescue (SAR) Mission

UAV SAR (0)

Execute mission (2.0)

Launch Monitor LandAircraft

(2.1)Mission

(2.2)Aircraft

(2.3)

MonitorStatus(2.2.1)

WatchVideo forVictims

ChangeCourse as

Needed

Move tolaunchpoint

TossA/C

(2.1.2)

Switch toComputerin Control

Send landcommand

2.3.1

Force A/CDown withRadio cntl

2.2.2 . .

Watch battery level (2.2.1.1)

Ensure GPS lock (2.2.1.2)

Monitor weather (2.2.1.3)

Enter loiter point if evidence

of victim nearby (2.2.3.1)Upload loiter point (2.2.3.2)

. . 2.1.3 . .

PLAN: if conditions turnunfavorable, immediately beginlanding sequence (2.3)

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Task analysis

perat ona sequence agrams or escr ngteam members actions

Graphic presentation of user tasks as they relatesequentially

Facilitates showing what multiple team members

are doing simultaneously ows m ng, ec s on po n s, ype o ac on

Purpose:

Useful for anal zin com lex s stems re uirin time-

critical decision making

Enables analysts to tease apart which team membersare doin what and when the are doin it

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Example

Illustration showsactions by twocrew members

ur ng a one-minute period

Legend is on nextpage

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Example

Legend for operational sequence diagram example

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Example: UAV preparation

Illustration shows

actions by twocrew members to

,necessary, zerothe attitude

adjustmentsett ng nresponse to achecklist item

rew o sthe aircraft whileCrew #1 checksthe settin

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Introduction to team workload analysis

time, so start with operational sequence diagrams Then characterize how bus each o erator is at each

moment based on direct observations

Are they manipulating an input device, monitoring the, ,

Could they do something more, or are they fully occupied?

Use estimates: 25%, 50%, 75% or 100% occupied

urpose: See where bottlenecks/overloads exist that could be

alleviated by less workload-intense approach

Determine if work could be redesigned to be done by fewer

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Task analysis

:

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