S.-Keshav---How-to-read-a-paper

HowtoReadaPaperJune26,2012S.KeshavDavidR.CheritonSchoolofComputerScience,UniversityofWaterlooWaterloo,ON,[e-mail]ndagreatdealoftimereadingresearchpa-pers.However,thisskillisrarelytaught,leadingtomuchwastedeffort.Thisarticleoutlinesapracticalandefficientthree-passmethodforreadingresearchpapers.Ialsode-scribehowtousethismethodtodoaliteraturesurvey.CategoriesandSubjectDescriptors:A.1[IntroductoryandSurvey]GeneralTerms:Documentation.Keywords:Paper,Reading,Hints.1.INTRODUCTIONResearchersmustreadpapersforseveralreasons:tore-viewthemforaconferenceoraclass,tokeepcurrentintheirfield,orforaliteraturesurveyofanewfield.Atypi-calresearcherwilllikelyspendhundredsofhourseveryyearreadingpapers.Learningtoefficientlyreadapaperisacriticalbutrarelytaughtskill.Beginninggraduatestudents,therefore,mustlearnontheirownusingtrialanderror.Studentswastemucheffortintheprocessandarefrequentlydriventofrus-tration.FormanyyearsIhaveusedasimpleapproachtoefficientlyreadpapers.Thispaperdescribesthe‘three-pass’approachanditsuseindoingaliteraturesurvey.2.THETHREE-PASSAPPROACHThekeyideaisthatyoushouldreadthepaperinuptothreepasses,insteadofstartingatthebeginningandplow-ingyourwaytotheend.Eachpassaccomplishesspecificgoalsandbuildsuponthepreviouspass:Thefirstpassgivesyouageneralideaaboutthepaper.Thesecondpassletsyougraspthepaper’scontent,butnotitsdetails.Thethirdpasshelpsyouunderstandthepaperindepth.2.1ThefirstpassThefirstpassisaquickscantogetabird’s-eyeviewofthepaper.Youcanalsodecidewhetheryouneedtodoanymorepasses.Thispassshouldtakeaboutfivetotenminutesandconsistsofthefollowingsteps:1.Carefullyreadthetitle,abstract,andintroduction2.Readthesectionandsub-sectionheadings,butignoreeverythingelse3.Glanceatthemathematicalcontent(ifany)todeter-minetheunderlyingtheoreticalfoundations4.Readtheconclusions5.Glanceoverthereferences,mentallytickingofftheonesyou’vealreadyreadAttheendofthefirstpass,youshouldbeabletoanswerthefiveCs:1.Category:Whattypeofpaperisthis?Ameasure-mentpaper?Ananalysisofanexistingsystem?Adescriptionofaresearchprototype?2.Context:Whichotherpapersisitrelatedto?Whichtheoreticalbaseswereusedtoanalyzetheproblem?3.Correctness:Dotheassumptionsappeartobevalid?4.Contributions:Whatarethepaper’smaincontribu-tions?5.Clarity:Isthepaperwellwritten?Usingthisinformation,youmaychoosenottoreadfur-ther(andnotprintitout,thussavingtrees).Thiscouldbebecausethepaperdoesn’tinterestyou,oryoudon’tknowenoughabouttheareatounderstandthepaper,orthattheauthorsmakeinvalidassumptions.Thefirstpassisade-quateforpapersthataren’tinyourresearcharea,butmaysomedayproverelevant.Incidentally,whenyouwriteapaper,youcanexpectmostreviewers(andreaders)tomakeonlyonepassoverit.Takecaretochoosecoherentsectionandsub-sectiontitlesandtowriteconciseandcomprehensiveabstracts.Ifareviewercannotunderstandthegistafteronepass,thepaperwilllikelyberejected;ifareadercannotunderstandthehigh-lightsofthepaperafterfiveminutes,thepaperwilllikelyneverberead.2.2ThesecondpassInthesecondpass,readthepaperwithgreatercare,butignoredetailssuchasproofs.Ithelpstojotdownthekeypoints,ortomakecommentsinthemargins,asyouread.Inparticular,DominikGrusemannfromUniAugsburgsug-geststhat“youmaywanttonotedowntermsyoudidn’tunderstand,orquestionsyoumaywanttoasktheauthor.”1.Lookcarefullyatthefigures,diagramsandotherillus-trationsinthepaper.Payspecialattentiontographs.Aretheaxesproperlylabeled?Areresultsshownwitherrorbars,sothatconclusionsarestatisticallysig-nificant?Commonmistakeslikethesewillseparaterushed,shoddyworkfromthetrulyexcellent.2.Remembertomarkrelevantunreadreferencesforfur-therreading(thisisagoodwaytolearnmoreaboutthebackgroundofthepaper).Thesecondpassshouldtakeuptoanhour.Afterthispass,youshouldbeabletograspthecontentofthepaper.Youshouldbeabletosummarizethemainthrustofthepa-per,withsupportingevidence,tosomeoneelse.Thislevelofdetailisappropriateforapaperinwhichyouareinterested,butdoesnotlieinyourresearchspeciality.Sometimesyouwon’tunderstandapaperevenattheendofthesecondpass.Thismaybebecausethesubjectmatterisnewtoyou,withunfamiliarterminologyandacronyms.Ortheauthorsmayuseaprooforexperimentaltechniquethatyoudon’tunderstand,sothatthebulkofthepa-perisincomprehensible.Thepapermaybepoorlywrittenwithunsubstantiatedassertionsandnumerousforwardref-erences.Oritcouldjustbethatit’slateatnightandyou’retired.Youcannowchooseto:(a)setthepaperaside,hopingyoudon’tneedtounderstandthematerialtobesuccessfulinyourcareer,(b)returntothepaperlater,perhapsafterreadingbackgroundmaterialor(c)persevereandgoontothethirdpass.2.3ThethirdpassTofullyunderstandapaper,particularlyifyouarere-viewer,requiresathirdpass.Thekeytothethirdpassistoattempttovirtuallyre-implementthepaper:thatis,makingthesameassumptionsastheauthors,re-createthework.Bycomparingthisre-creationwiththeactualpaper,youcaneasilyidentifynotonlyapaper’sinnovations,butalsoitshiddenfailingsandassumptions.Thispassrequiresgreatattentiontodetail.Youshouldidentifyandchallengeeveryassumptionineverystatement.Moreover,youshouldthinkabouthowyouyourselfwouldpresentaparticularidea.Thi