PairProgrammingintheClassroom

MarkSherriffUniversityofVirginia

June28,2017

SomematerialcourtesyofLaurieWilliams,NCSU

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Overview• WhatexactlyisPairProgramming?• TheCaseforPairProgramming• TheCosts• Guidelinesforasuccessfulpairingexperience• MythsandLegends• Resources

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PairProgrammingDefinition• "Pairprogrammingisastyleofprogramminginwhichtwoprogrammersworkside-by-sideatonecomputer,continuouslycollaboratingonthesamedesign,algorithm,code,ortest."– LaurieWilliams

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SlightlyAlteredDefinition• "Pairprogrammingisastyleofprogramminginwhichtwoprogrammersworkside-by-sideatonecomputer,continuouslycollaboratingonthesamedesignoralgorithm."(emphasismine)

• Basicidea:IDE’shelpuscode– peoplehelpusdesign!

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WhyPairProgramming?• Pairprogrammingstudentstendto:

– Makeitthroughthefirstclass– Improvesretention– Increasesprogrammingconfidence– Performcomparablyorbetteronexamsandprojects

– Performjustfineinfuturesoloprogramming– Helpcreatepeergroups

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WhyPairProgramming?• Aninstantsupportsystem

– Wehavefoundthatpairingcutsdownonalargenumberofthe"trivial" questions(syntax,assignmentclarification,etc.)andafairnumberofthemorecomplexquestions(debugging,etc.)

– WehavebeenabletoreducethenumberofTAsforsomecourses

– Instructorofficehoursaremuchquieter,andtheinstructorcanspendmoretimewithstudentsthatneedmorehelp

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WhyPairProgramming?• Sometimesitis anumbersgame• Inalabof40students…

– having20pairsmakesiteasierforTAstogettoeveryone

– 20assignmentsareeasier/fastertogradethan40• OurmainCS1coursehasonaverage500studentsasemester…

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TheRoles• TheDriver

– Thepersonwith"control" ofthecomputer– Doesthebulkofthetyping

• TheNavigator– Activelyfollowsalongwiththedriverwithcomments

– Cantakeoveratanytime• Howdoesthistranslatetopairdesign?

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Partnersvs.PairProgramming• HowisPairProgrammingdifferentthanjusthavingpartnerassignments?– Mentalityofhowtoapproachtheassignment

• Partnering:– "YougodothispartandI’llgodothispartandthenwe’ll putitbacktogether."

• PairProgramming:– "Let’sfirstdothisparttogether,thenwe’lltackletherest."

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Partnersvs.PairProgramming• Thedistinctionmatters!• Itmattersto:

– Instructors– TeachingAssistants/Tutors– Students

• Callitframing,perception,spin…whatever• It’sallaboutattitude!

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It’sAllAboutAttitude• Howdoyougettheattitudegoing?• HowdoIstartusingpairprogramming?• Thingstoconsider:

– TeachingtheTechnique– Assignments– PairCreation– PairEvaluation– Assessment

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TeachingtheTechnique• Startwiththeinstructionalstaff• PairprogrammingHAStobeincorporatedintotheclass(orlab)insomestructuredway

• Studentsdonotnaturallyworkasa“pair”whengivena“partner”

• Whathappenswhenyoutellstudentstheycanworkwitha“partner”?

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TeachingtheTechnique• Theenvironmentmatters!

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TeachingtheTechnique• Whatareyouactuallyteachingthemtodo?• 1.Taketurnsbeingtheonecoding(“driver”)• 2.Whoeverisnotcoding,commentactively• 3.Whoeveriscoding,talkthroughwhatyouaredoing

• 4.Switchatregularintervals• 5.Nothingisdoneindependentlyfromtheotherpartner

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TeachingtheTechnique• Switchingrolescanbeproblematics• Someideas:

– Goaroundandtappeopleontheshoulder– Haveaaudiocue– Haveavisualcue

• Trytoenforceevenrolesasmuchaspossible• Trytoenforceno“splittingupwork”asmuchaspossible

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Assignments• DoIhavetototallychangemycoursematerialtodopairprogramming?

• Answer:Probablynot,butsomechangesmightmakethingsgobetter

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Assignments• Biggestproblem:assignmentscope• Ifyouuseyourcurrentassignmentswithnomodificationatall,it’spossiblethatnoswitchingwilloccurand/orthepointofpairingwon’tbeobvious

• Example:ConvertFahrenheittoCelsius• CounterArgument:Twonoviceslearningtogetherfromtheverybeginningcouldhelpwithself-confidence

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Assignments• Iftheassignmentscopeistoolargeorifthereisanobvious“splitpoint”,divideandconquerbecomesmoretempting

• Example:WriteaStudentandCourseclassthatworktogethertokeepupwithcourseenrollment

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Assignments• AnassignmentIlikeforpairprogramming:• EmailHunt

– Givenawebsitethathasabunchofemailaddressesonit,writeaprogramthatcanreadthewebsiteandextracttheemailaddresses

– http://cs1110.cs.virginia.edu/emails.html• ThingsIlike:

– Noonewaytodoit(infact,ittakesmorethanoneideatogetalltheemailsout)

– Allowsforsomecreativity19

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PairCreation• Howdoyoucreatepartners?• Bigphilosophicquestion:

– Doyouassignpartnersordoyouletstudentspicktheirownpartners?

– Advantagesanddisadvantagestoboth

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PairCreation– AssignedPairs• Howcanyouassignpairs?

– Randomly– Basedonprogrammingexperience/confidence– Personality/friendships– Otherinterests/surveyresults

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PairCreation– AssignedPairs• Randomly

– Easiesttosetup– Goodifyouhavenootherinformationtoworkfrom

– Haspotentialtoleadtoproblems(butnotasmanyasyoumightthink)

– Consider“randomwithreplacement”forsubsequentassignments(noonecanworkwithsamepersontwice)

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PairCreation– AssignedPairs• Basedonprogrammingexperience/confidence– Researchindicatesthishasthehighestlikelihoodofproducinggoodpartnerships

– Hardtosetupuntilyouhavedata– Eventhen,itcanbedifficultbecauseresearchshowsthatperception ofpartner’sability(notactualability)isahigherindicatorofagoodmatch

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PairCreation– AssignedPairs• Personality/Friendships

– Mostlikelytohavethefewestpersonalityconflicts– Enforcingcliques

• Othersurveyresults– Ihaven’tusedanythingelse,butcouldimagineusingthingslike:• Schedule• Outsideinterests• Commonfriends

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PairCreation– Self-SelectedPairs• Self-selectedpairsoftenhaveelementsoftheassignedpairingswithsimilarexperienceandfriendships

• Soithassimilarbenefitsanddrawbacks• However,youHAVEtomonitorcloselyforthe“laststudentpicked”problem

• Probablyshouldenforcereplacementforlaterassignments

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PairReplacement• Reassignseveraltimespersemester• Goodforstudents

– Gettomeetnewpeople,learnaboutworkingwithnewpeople

– Iftheydon’tliketheirpartner,theyknowtheywillgetanewonesoon

• Goodforinstructor– Multipleformsoffeedback– Naturalhandlingofdysfunctionalpairs

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PairManagementandEvaluation• Auto-AssignPairCreation

– CATME– http://www.catme.org– Dataneededtoauto-createpairsvaries

• Self-ReportedPairs– GoogleForms

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PairEval

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PairEval

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PairEvaluation• Withorwithoutatool,itboilsdowntoafewquestions:– Didthepairgetalong?– Didyougettheworkdone?– Doyoufeellikeyou“didyourfairshare?”

• Moredataisnice/interesting,butthisisallyoureallyneed

• Reliablefeedbacksystemisneeded(bothforyouandthestudents)

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PairEvaluation• NCWITresourceshavesurveysyoucanuse!• Exampleinyourpacket• http://www.ncwit.org/pairprogramming

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PairEvaluationandAssessment• Ifthere’snoproblem…thengreat!• Ifthereis…

– Ifpossible,askthestudentsoneatatime:“If100%effortisyoudoingexactlywhatyoushouldhavebeendoing,whatpercentagedidyouactuallydo?”

– 95%ofthetime,thisworks!– Fortheother5%,youhavetouseyourbestjudgement

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Assessment• Forotherclassassessments,Idonotadjustanything

• Alltests/exams,popquizzes,etc.allstaythesameasifitwereasoloprogrammingonlycourse

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TheBiggestCost• Training!• Instructors,TAs,andstudents needtobetaughthowtodoeffectivepairprogramminginacontrolledenvironment!

• Thecontrolledenvironmentcouldbeaclosedlaborlecture-labsystem

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Butwedon’thaveaclosedlab?• CS1:

– Assignedpairsnotadvisableiftheydon’tknowthepartnersTrytointroduceinguidedlabs/in-classactivitiesfirst

• CS2:– Proceedwithcautionforassignedpairsforfirstassignment– Worksbetterafterfirstmonthorso– Atleastbondinlab+someoutsidework

• CS2+:– Afteratleastonepairedclass– Bondingstillbeneficial,outsideworkfine

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GettingInvolved• InstructorsandTeachingAssistantshavetotakeanactiveroleinlab– Mustmonitorandapproachpairsiftheyseemtobedysfunctional

– Should"stronglyencourage" driversandnavigatorstoswitch

• Instructorsalsomustunderstandthatsomepairingsarejustnotgoingtowork– Don’tletitdiscourageyou!

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HowManyPairingsFail?

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Class Verycompatible

OK Notcompatible

CS1 64% 32% 4%

SE-P1 60% 33% 7%

SE-P2 56% 35% 9%

OO 76% 15% 9%

Total 60% 33% 7%

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ProblemPairs• Willproblempairshappen?Yes.• Particularcases:

– The“Idon’tcare”student– Thespecialneedsstudent– Theabsentstudent– The“liberalartsvs.engineering”student

• Theseproblemsarenotpairprogrammingrelated,butpairprogrammingcanmakethesecometothesurfacemoreoften

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GuidelinesToFollow• Stricttardiness/absencepolicymustbefollowedforpairactivitiestoguardagainstlazypartners.– Lossofpartner,points,andbadevaluation

• Theremust beareportingmechanismforstudentstoprovidefeedbackonpartners– CATMEorasimpleGoogleForm– "Ifyoucouldrateyoureffortbasedon100%.."

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GuidelinesToFollow• Assignmentsshouldbeabitmorechallenging

– "Softball" assignmentstendtobefinishedbyasinglepersonwithoutconsultingtheirpartner

• Theenvironmentforpairingmustbeconducivetopairing

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GuidelinesToFollow• Don’tgooverboard!

– EverythinginmoderationJ– Pairingisn’tforeveryassignment– Theremustbeabalance(inworkandingrade)

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MythsandLegends• Myth:Halfthestudentswilllearn

– "Inthefirstcourse,studentsneedsometimetoabsorbtheideasthemselves."

– "Myinclinationistoallowmoregroupworkstartinginthesecondcourse."

– "Wewanttobesurethateachstudentwritesenoughcodehim/herselftolearntheintroductoryconcepts."

– "Iamagainstpair-programminginintroductorycourses,wherestudentsneedtodevelopstrongprogrammingskillsthemselves."

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MythsandLegends• Infact,allthestudentslearnprettywell…

– StudiesatNCSUandSDSUshowedthatexamscoreswerecomparableorimprovedforallstudentsinintroductoryclasses

– Also,thepercentageofstudentswhosegradeinCS2wentdownbyover1/3ofagradedroppedoncepairingwasusedinCS1

Williams,L.,Layman,L.,LabPartners:IfThey’reGoodEnoughfortheSciences,WhyAren’tTheyGoodEnoughforUs?,ConferenceonSoftwareEngineeringEducationandTraining(CSEE&T’07)

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MythsandLegends• Byfallingforthismyth,you’reperpetuatinganotherone– “Allcomputerscientistworkbythemselvesincubiclesstrugglingtocode.”

• WeallknowthatcreatingsoftwareisHIGHLYcollaborative!

• Whygivethewrongimpressioninthefirstclasstheytake!?

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MythsandLegends• Myth:Cheatingwillincrease

– "Withlooserulesaboutwhopartnersare,peoplewilljustpasscodearound.Therehastobestructure!"

– "Oldpartnersmayfeelobligedtohelptheirformerteammates."

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MythsandLegends• Thinkaboutitalittledifferently…• Whenweprovidepartners,studentsnowhaveasupportsystemtheycanturnto– Anecdotalevidencefromstudentsindicatedthatthestressoffeelingaloneandisolatedmadethemconsidercheating

• Twopeoplenowhavetoagreeoncheating!– Well…thereareexceptionstothisone…– Mossandetector arevaluabletools

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OtherGuidelinesandMyths• Anyotherstoadd?

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Resources• http://www.realsearchgroup.org/pairlearning• http://www.ncwit.org/pairprogramming

• Mypersonalwebsite:http://marksherriff.com

• Myemail:sherriff@virginia.edu

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