software%development%in%teams%&%organizations...

SENG%403%–%Software%Development%in%Teams%&%Organizations

Software%UsabilitySoftware%Development%in%Teams%&%Organizations

442 SENG%403%–%Software%Development%in%Teams%&%Organizations

Usability

! A%quality%attribute%that%assesses%how%easy%user%interfaces%are%to%use.%

! Defined%by%five%components:! Learnability:%ease%of%finishing%tasks%for%the%1st%time.! Efficiency:%how%quickly%users%can%perform%tasks! Memorability:%how%easily%users%are%able%to%reestablish%proficiency%in%using%the%system.%

! Errors:%quantity%of%errors,%severity,%and%recovery! Satisfaction:%how%pleasant%it%is%to%use%the%design.

443


Usability

1 Message

2 Receiver:%?


Usability

1 Receiver:%John%Smith

2 Message

445


Significance

! What%is%useful%software?! It%does%what%users%need%(utility).! The%user%can%make%it%do%what%it%says%it%can%do%(usability).%

! One%aspect%without%the%other%may%well%render%the%software%useless.%

! Users%always%gravitate%towards%the%easier%solution.%Example?


Significance

! For%the%web,%usability%is%a%necessary%condition%for%survival.! The%first%law%of%eZcommerce%is%that%if%users%cannot%find%the%product,%they%cannot%buy%it%either.

! For%internal%systems,%usability%is%a%matter%of%employee%productivity.! Time%users%waste%dealing%with%unusable%software%is%money%you%waste%by%paying%them%to%be%at%work%without%getting%work%done.

447


Usability%Testing

! Usability6Testing6(evaluation):6methods%to%evaluate%and%improve%easeZofZuse%during%the%design%process.

! Is%it%free?! Absolutely%not.%


Usability%Testing

! Management:%Great%idea!%How%much?

Focus%%group%%(2%sets%%of%%3%$6285) $12,570%

Product%%mockup $3,760

User%%survey%%(3%@%$7,200)% $21,600

Lab%%construction $17,600

Initial%%design $6,400%

Design%%change%%(20%%@%%$320)% $6,400

UIMS%%system $16,080

User%%study%%(6%%@%%$7,320) $43,920

Total $128,330

%%

Mantei,%M.%M.,%and%Teorey,%T.J.%(1988).%Cost/benefit%analysis%for%incorporating%human%factors%in%the%software%lifecycle,%Communications%of%the%ACM%31,%4%(April),%428Z439.

449


Economic%Justification

! Do%discount%methods%still%cost%money?! Yes.

! How%can%we%justify%the%investment?! For%a%corridor%talk%with%the%manager,%stress%obvious%advantages.%Like%what?

! When%numbers%are%needed,%use%a%benefit/cost%analysis.%How?


Discount%Usability

! MiniZversion%of%usability%methods! Cheap,%timely%&%easily%accessible

! $thousands,%hours,%a%handful%of%people! Coined%by%Nielsen%and%others! Values:

! observation%over%complex%statistics.%! flexibility%over%expensive%labs.

451


Discount%Usability%Methods

! Heuristic%Evaluation! Card%Sorting! Think%Aloud! Walkthroughs


Heuristic%Evaluation

The%system

Usability%Heuristics

Evaluators

Usability%Evaluation

453


How%it%works%Z%Procedure1%Get%the%heuristics

2%Get%the%system%ready

3%Get%the%evaluators

4%Do%the%evaluation

5%Compile%the%results

6%Conduct%severity%rating

7%Develop%an%action%plan


Get%the%heuristics

! Heuristics%are%system%dependent.! Nielsen’s%heuristics%proved%reliable%&%representative.

! Feel%free%to%add%more%heuristics%but%not%many.%! Feel%free%to%drop%irrelevant%ones.%

455



! Visibility%of%system%status



! Match%between%system%and%the%real%world%

457



! User%control%and%freedom



! Consistency%and%standards

Greenberg,%S.,%Overview%of%Heuristic%Evaluation,%http://pages.cpsc.ucalgary.ca/~saul/%wiki/uploads/CPSC681/Heuristic.ppt,%accessed%October%10,%2007.

459



! Error%prevention



! Help%users%recognize,%diagnose,%and%recover%from%errors%

461



! Recognition%rather%than%recall



! Flexibility%and%efficiency%of%use! Shortcuts:%

! Normal%mode%vs.%Advanced%mode! Don’t%make%it%the%only%way.

Ctrl C Copy

463



! Aesthetic%and%minimalist%design%



! Help! Help%should%be%concise,%easy%to%reach,%and%taskZcentered.

! Help%documents%should%be%supported%with%examples.

! People%do%not%read%long%documents.

465


! Procedure

466

1%Get%the%heuristics



4%Do%the%evaluation





Get%the%system%ready! Prototype:%novel%application%or%interface

! No%redesign%required! Less%maintenance%later

! Working%system:%replacement%study%or%competition

! Prepare%typical%scenarios:%task%analysis

467


How%it%works%Z%Procedure! Procedure

468




4%Do%the%evaluation





Get%the%evaluators! Heuristic%evaluation%is%a%group%effort.

Nielsen,%J.,%and%Mack,%R.L.%(Eds.),Usability%Inspection%Methods,%p25Z62.%John%Wiley%&%Sons,%New%York,%NY%(1994).

469


Get%the%evaluators! The%more%the%better?%Not%necessarily! Rule%of%thumb:%3%to%5%evaluators

Nielsen,%J.,%and%Mack,%R.L.%(Eds.),Usability%Inspection%Methods,%p25Z62.%John%Wiley%&%Sons,%New%York,%NY%(1994).


Get%the%evaluators! Evaluators’%expertise

! Novices:%better%be%potential%users%of%the%system! Usability%experts:%more%effective! Double%experts%(both%in%usability%and%the%domain):%the%best%to%get%but%very%expensive

! Session%manager:%facilitates%the%evaluation%session%&%aggregates%reports%

! Observers:%provide%help%to%evaluators

471



472




4%Do%the%evaluation





Do%the%evaluation

! Evaluators%get%the%heuristics%&%scenarios.%! Navigate%through%the%system%twice.%! Inspect%screens,%dialogues,%forms,%messages%and%menus%in%the%system.

! Categorize%any%problem%under%one%of%the%heuristics:%should%give%specific%explanation.

! Can%make%comments%beyond%the%heuristics.%! Report%in%writing%or%verbally%to%the%observer.

473


Do%the%evaluation

! Observers%answer%evaluators’%questions.%! especially%domainZspecific%questions.! but,%without%influencing%judgments.

! IMPORTANT:! Inspection%should%be%done%individually.! Evaluators%are%not%allowed%to%communicate.

! Session%takes%1%to%2%hours.


How%it%works%Z! Procedure

475




4%Do%the%evaluation





Compile%the%results! Aggregate%evaluators’%reports.

! Eliminate%duplicate%entries.! Merge%different%problems.

! Output:%One%report%of%all%usability%problems%found%by%the%evaluators.


! Procedure

477




4%Do%the%evaluation





Conduct%severity%rating! Evaluators%are%aware%of%all%usability%problems.! Severity%determined%by:

! frequency%of%occurrence! impact%on%user! persistence

0: Not a problem at all

1: Cosmetic problem

2: Minor problem

3: Major Problem

4: Catastrophic problem



479




4%Do%the%evaluation





Develop%an%action%plan! Evaluators,%facilitator%&%the%design%team%meet.

! Discuss%problems%.! Suggest%solutions.

! Consider%organization’s%priorities.! Take%decisions:%fix%major%not%minor%problems,%change%the%release%plan,%replace%interface%…%etc.


Exercise

481


ExerciseUsability)HeuristicsUsability)Heuristics

1.%Visibility%of%system%status 6.%Recognition%rather%than%recall

2.%Match%between%system%and%the%real%world 7.%Flexibility%and%efficiency%of%use

3.%User%control%and%freedom 8.%Aesthetic%and%minimalist%design

4.%Consistency%and%standards 9.%Help%users%recognize,%diagnose,%and%recover%from%errors

5.%Error%prevention 10.%Help%and%documentation

Severity)RatingsSeverity)Ratings

0 this%is%not%a%usability%problem%at%all.%

1 cosmetic%problem%only%Z%should%be%fixed%only%if%extra%time%is%available.%

2 minor%usability%problem%Z%fixing%this%should%be%given%low%priority.%

3 major%usability%problem%Z%important%to%fix,%so%should%be%given%high%priority.

4 usability%catastrophe%Z%imperative%to%fix%this%before%product%can%be%released.%


Card%Sorting

! Especially%effective%for:! Information%distribution! Feature/command%grouping

! Every%entry%on%an%index%card.! Participants%group%entries.! Participants%put%groups%into%larger%piles.

483


Card%Sorting%Z%Sun%Website

! Brainstorming%or%release%planning%Z>%40%titles.! Target:%Group%40%titles%into%4%to%6%categories%! Write%the%40%titles%you%have%on%index%cards

http://www.dcc.unicamp.br/~hans/mc750/uidesign/cardsort.html484 SENG%403%–%Software%Development%in%Teams%&%Organizations

Card%Sorting%Z%Sun%Website

! Participant:! groups%these%titles%into%piles.! gives%each%pile%a%descriptive%name.! keeps%grouping%until%he%can%go%no%further.

! Usability%Tester:! Finds%commonalities%between%users.! Comes%up%with%a%final%set%of%categories.

Products%(11),%Downloads%(11),%Services%(8),%Support%(6),%Training%(4)

http://www.infodesign.com.au/usabilityresources/design/cardsorting.asp

485


Card%Sorting%Z%Comments

! One%line%description%may%be%added%on%the%index%card.

! Tester%should%not%specify:! Group%size! Number%of%groups

! Sorting%takes%about%30%minutes/user! Proactively%%enhances%usability


Think%Aloud

! Participants%operate%on%a%real%system%(or%a%prototype).

! Participants%speak%out%their%minds:! What%to%do?%How%to%do%it?%Why%this%way?

! Example:

IBM's6RealPhone,6http://homepage.mac.com/bradster/iarchitect/phone.htm

487


Think%Aloud

! If%the%same%behavior%is%repeated%with%a%number%of%participants,%then%a%change%may%be%necessary.

! Conclusion:! It%is%more%intuitive%to%dial%the%number%first%and%then%issue%a%command%to%make%the%call.%

! Notice:%! User%may%not%say%why%(too%intuitive%to%explain).%! An%observer%needs%to%be%there%–%video%taping%may%help.! Only%few%minutes%to%perform%&%analyze%a%task.! What%do%you%do%with%silent%participants?


Walkthroughs

! Focused%evaluation! Use%taskZcentered%walkthroughs%

1.%Define%the%targeted%audience

2.%Prepare%tasks%for%the%targeted%audience

3.%Specify%the%amount%of%knowledge%needed

489


Walkthroughs%Z%Example

1. Define%the%targeted%audience! People%migrating%from%MS%Word%2003%to%2007

2. Prepare%tasks%for%the%targeted%audience! Finding%the%word%count%! Making%the%background%of%an%image%transparent

3. Specify%the%amount%of%knowledge%needed! Participants%need%to%know%what%word%count%&%

transparent%background%mean,%and%they%need%to%know%how%to%do%these%tasks%using%Word%2003.


Walkthroughs%Z%Procedure

! SELECT%one%of%the%defined%tasks%and%a%potential%user! FOR6EACH%user’s%action%WHILE%performing%the%task:! IF%the%user:

! Cannot%anticipate%what%is%to%be%done%nextOR

! Does%not%seem%to%have%sufficient%knowledge%to%do%it%! THEN

! There%is%a%problem%in%the%interface%at%this%point! Note%the%problem%and%any%comments%or%solutions%! Tag%the%problem%as%repaired

! PROCEED%to%the%next%step%in%the%task

Lewis%&%Reiman%(1993)%Task%Centered%User%Interface%Design:%A%Practical%Introduction.%University%of%Colorado,%Boulder.%Shareware%book%available%from%ftp.cs.colorado.edu/pub/cs/distribs/clewis/HCIDesignZBook/

491


Requirements%features%1Z15

Designfeatures%1Z15

Implementation

features%1Z15

Quality%Assurance

features%1Z15

Usability%Evaluation Usability%Evaluation

Traditional%Usability%Evaluation


Agile%Usability%Evaluation

Designfeatures%

1Z5

Quality%Assurancefeatures

1Z5

Designfeatures%%6Z10

Quality%Assurance

features%%6Z10

Designfeatures%%11Z15

Quality%Assurance

features%%11Z15

Usability%Evaluation Usability%Evaluation

493


Possible%Approach

Sy,?D.?Adapting?usability?investigations?for?agile?userCcentered?design.?Journal?of?Usability?Studies,?Vol.?2,?No.?3,?May?2007


Advantages%of%Discount%Methods! Easy%to%teach%&%easy%to%comprehend! Fast%to%conduct%! Cheap:%no%laboratories%or%expensive%equipment! Don’t%necessarily%require%usability%experts! Don’t%necessarily%require%a%working%system%! Can%be%used%in%early%design.! High%benefit%to%cost%ratio:

! In%a%case%study:%a%ratio%of%48%(conservatively)

495


Shortcomings%of%Discount%Methods! Oversimplification%or%distortion

! Example:%reduced%set%of%heuristics%is%very%broad%and%general

! May%not%involve%endZusers! Finds%many%minor%problems%causing%a%“false%alarm”%sometimes.%

! Limitation:%not%suitable%for%inZdepth%usability%testing%or%for%evaluating%critical%systems.


Keep%in%mind! Usability%may%be%a%necessity%NOT%a%luxury.

! “Launching%a%site%that%is%difficult%to%use%means%that%you%not%only%lose%your%best%customers%but%they%will%also%warn%others%not%to%visit%the%site."%(Nielsen).

! Usability%does%NOT%have%to%be%expensive%&%timeZconsuming%to%be%effective.

! Variety%of%methods:%card%sorting,%thinkZaloud,%walkthroughs,%scenarios%&%heuristic%evaluation.

497


References%&%Readings

! Curtis,%B.,%Nielsen,%J.%(1995).%Applying%Discount%Usability%Engineering.%IEEE?Software,%vol.%12,%%no.%1,%%pp.%98Z100.

! Nielsen,%J.,%Guerrilla%HCI:%Using%Discount%Usability%Engineering%to%Penetrate%the%Intimidation%Barrier,%http://www.useit.com/papers/guerrilla_hci.html,%accessed%18%Oct,%2007.

! Nielsen,%J.,%and%Molich,%R.%(1990).%Heuristic%evaluation%of%user%interfaces,%Proc.?ACM?CHI'90?Conf.?(Seattle,%WA,%1Z5%April),%249Z256.

! Nielsen,%J.,%and%Mack,%R.L.%(Eds.),%Usability%Inspection%Methods,%p25Z62.%John%Wiley%&%Sons,%New%York,%NY%(1994).

! Sy,%D.%Adapting%usability%investigations%for%agile%userZcentered%design.%Journal?of?Usability?Studies,%Vol.%2,%No.%3,%May%2007.

498

software%development%in%teams%&%organizations...

Documents