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Researchinphysicseducation:Aresourceforimprovingstudentlearning
LillianC.McDermottPeterS.ShafferUniversityofWashington
NewPhysicsandAstronomyFacultyWorkshop
June2017
PhysicsEducationGroupattheUniversityofWashington
PhysicsPh.D.Graduates25(1979-2017)
PhysicsPh.D.StudentsAnneAlesandriniDeanBretlandShehLitChangKevinCutlerLisaGoodhewAlexisOlshoTongWanBertXue
FacultyLillianC.McDermottPaulaHeronPeterShafferSuzanneWhite-Brahmia
Lecturers&Post-docsDonnaMessina(K-12teacher)RyanHazelton
Coordinatedprogramofresearch,curriculumdevelopment,andinstructionissupported,inpart,bygrantsfromtheNationalScienceFoundation.
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Summaryofworkshop
• OverviewofresearchandcurriculumdevelopmentbyUWPhysicsEducationGroup
• Directexperiencewithcurriculum(aTutorialfromTutorialsinIntroductoryPhysics)
• Discussionofimpactonstudentlearning
• Generalizationsontheteachingandlearningofphysics
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GoalsofUWPhysicsEducationGroup
• Conductresearchonlearningandteachingofphysicsconceptsandreasoning(differsfromtraditionaleducationresearch)
• Developinstructionalproceduresthat:– areeffectiveathelpingstudentslearn(conceptsandreasoning)– yieldsimilarresultswhenusedbyfacultyatotherinstitutions
• Documentimpactandproceduresinjournalsthatarereadbyphysicsfaculty(writteninlanguageaccessibletophysicists)– Tohelpallfacultyimprovetheeffectivenessofinstruction
whetherornottheyareengagedinphysicseducationresearch.
JointAAPTandAPSresolutions(1999)encouragingphysicsdepartmentstoengagein:(1)physicseducationresearchand(2)thepreparationofK-12teachers
• StrengthenthepreparationofK-12teacherstoteachphysicsandastronomybyinquiry
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Inworkingtowardthesegoals,wehavecometoanimportantgeneralization:
Oncertaintypesofqualitativequestions,studentperformanceisessentiallythesameoverawiderangeofstudentability:
• beforeandafterstandardinstruction• incalculus-basedandalgebra-basedcourses• withandwithoutstandarddemonstrations
• withandwithoutstandardlaboratory• inlargeandsmallclasses
• regardlessofpopularityoftheinstructor
Hearinglectures,readingtextbooks,seeingdemonstrations,doinghomework,andperforminglaboratoryexperimentsoftenhavelittleeffectonstudentlearning.
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Evidencefromresearchindicatesgap
Instructor
Student
Curriculum
Gapgreaterthanmostinstructorsrealize6
◊ Teachingbytellingisanineffectivemodeofinstructionformoststudents.
Teachingbyquestioningcanbemoreeffective.
Studentsmustbeintellectuallyactive
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Caution:
“activelearning”doesnotalwaysleadto
“intellectualengagement”
Documentedresearchisnecessarytodeterminethedepthofunderstanding.
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Systematicinvestigationsofstudentlearning(atthebeginning,during,andafterinstruction)
• individualdemonstrationinterviews• forprobingstudentunderstandingindepth
•writtenquestionswithexplanations(pretestsandpost-tests)
• forascertainingprevalenceofspecificdifficulties• forassessingeffectivenessofinstruction
•descriptivestudiesduringinstruction• forprovidinginsightstoguidecurriculumdevelopment
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CurriculumDevelopmentResearch
InstructionatUW
Instructionatpilotsites
Applicationofresearchtodevelopmentofcurriculum
Research-based≠Research-validated10
Research-basedcurriculumdevelopment
Preparingprecollegeteacherstoteachphysicsandphysicalscience
– PhysicsbyInquiry–(JohnWiley&Sons,Inc.,1996)
Self-contained,laboratory-based,nolectures
Improvingstudentlearninginintroductoryphysics
– TutorialsinIntroductoryPhysics–(PrenticeHall,2002)
Supplementarytolecture-basedcourse
Tutorialsrespondtotheresearchquestion:
Isstandardpresentationofabasictopicintextbookorlectureadequatetodevelopafunctionalunderstanding?
(i.e., theabilitytodothereasoningnecessarytoapplyrelevantconceptsandprinciplesinsituationsnotexplicitlystudied)
Ifnot,
whatneedstobedone?
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Emphasisintutorialsis
on
• constructingconcepts
•developingreasoningability
• relatingphysicsformalismtorealworld
not on
• solvingstandardquantitativeproblems
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Primarycontext(atUW)fortutorials
Eachweek:• 3lectures(50minutes)
• 1laboratory(2-3hours)
• 1tutorial(50minutes)
However,usecanvary(e.g., inlecturesorlabs)dependingonconstraintslike
classsize,roomavailability,numberoflecturers,
numberofTAsorpeer-instructors,etc.
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TutorialComponents•weeklypretests• givenusuallyafterlectureonrelevantmaterialbutbeforetutorial
• tutorialsessions• smallgroups(3-4)workthroughcarefullystructuredworksheets• tutorialinstructorsquestionstudentsinsemi-Socraticmanner
• tutorialhomework
Additionalcriticalcomponents
• examinationquestions– allexamsincludetutorialpost-testquestions(tohelpensurestudents
takeseriouslythefocusonunderstandingemphasizedintutorial)
• requiredweeklyseminarfortutorialinstructors– TA’s,peerinstructors,etc.– preparationincontentandinstructionalmethod– TAstakepretest,workthroughtutorial,anddiscussstudentresponses.
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Exampleoftutorial:Dynamicsofrigidbodies
• Pretest- Pleasecompleteonyourown;takenomorethanabout5minutestoanswer.
• Tutorial-Pleaseworkinsmallgroups-Therewillbefull-workshopdiscussions(nottypicalofsmallgrouptutorialsessions*)
• Assessmentoftutorialandgeneralizations
*SimilarinstructuretoTApreparationsessions
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Dynamicsofrigidbodies,page1Aspoolispulledacrossafrictionlesstableasshown.Thehandpullshorizontally.Thethreadhasbeenwrappedmanytimesaroundthebottomofthespool.
• Predict whetherthespoolwillrotate.Explain.
• Predict whetherthecenterofthespoolwillmoveandifso,inwhichdirection.Explain.
Testyouranswersbyperformingtheexperimentonatablewith friction.
Asinstructors,thinkaboutanswersthatstudentsmightgivetothesetasksandwhatitmightindicateabouttheirthinking.
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Whatdoyouranswerssuggestaboutwhatwouldhappenifthetablewerefrictionless?
observevideo(asagroup).
Spoolonairtable(negligiblefriction)
Dynamicsofrigidbodies,page1Aspoolispulledacrossafrictionlesstableasshown.Thehandpullshorizontally.Thethreadhasbeenwrappedmanytimesaroundthebottomofthespool.
• Predict whetherthespoolwillrotate.Explain.
• Predict whetherthecenterofthespoolwillmoveandifso,inwhichdirection.Explain.
Testyouranswersbyperformingtheexperimentonatablewith friction.
Asinstructors,thinkaboutanswersthatstudentsmightgivetothesetasksandwhatitmightindicateabouttheirthinking.
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Whatdoyouranswerssuggestaboutwhatwouldhappenifthetablewerefrictionless?
observevideo(asagroup).
Examplesofstudentresponsestospoolsquestionfrompage1(whengivenaspretest)
Thespoolwillrotateandnottranslate
• “Theforceofthestringwillcausetorque....Thereisnoforceapplieddirectlytothespooltomakeitgoforward.”
Thespoolwilltranslateandnotrotate
• “Thereisnofrictionduetothesurfacesothe… particlesontheotherside[ofthespool]havenoforcekeepingitput- sothespoolwillnotrotate.”
• “onafrictionlesssurface.Thetensionwillnotgeneraterotationbecausethereisnoforceactingintheoppositedirectiontogeneraterotation.… forrotationtobegin,theremustbeaforceactinginthepositiveandnegativedirectiononthespoolandinthiscase,thereisnonegativeforce.”
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Forcenotatcenterofmassresultsinrotationonly.
Forcenotatcenterofmassresultsonlyintranslationofentireobjectunlessanotherforceactstorotateobject
Dynamicsofrigidbodies,page2Ablockandspoolareeachpulledacrossalevel,frictionlesssurfacebyastring.• Predict theorderinwhichtheycrossthefinishline.
• Threestudentsdiscusstheexperiment.1. Thespoolrotatesandbothfinishatthesametime …
samemassandnetforcesothecentershavethesameacceleration.Thetensionshavethesameeffectontranslationalmotion.
2. Thespoolcrossesaftertheblock.Sometensionisusedtorotatethespool.Whenaforcecausesrotation,ithaslesseffectontranslation.
3. Iagreethespoolrotatesandcrosseslater,butIwasthinkingaboutenergy.Theyhavethesametotalkineticenergyatthefinishline.SincethespoolhassomerotationalKE,itmusthavelesstranslationalKE.
Withwhichstudentdoyouagree?
Continuetopage3whenyouandyourpartnersareready. 23
Dynamicsofrigidbodies,page3
Twoidenticalspoolsareconnectedbyathreadthatrunsoveranidealpulley.ThethreadiswrappedaroundspoolAmanytime,butisattachedtoafixedpointonspoolB.
Thespoolsarereleasedfromthesameheightatthesametime.
• Predict whetherspoolAwillhitthefloorbefore,after, oratthesametimeas spoolB.
• Drawthefollowingdiagramsforeachspool,correspondingtoatimeshortlyaftertheyarereleased:o anextendedfree-bodydiagramo a(point)free-bodydiagram
• Whatwouldeachstudentonthepreviouspagepredict?
Wewilldiscusstheanswersandobserveavideoasgroup.24
Dynamicsofrigidbodies,page3
• Drawforeachspool:• anextendedfree-bodydiagram• a(point)free-bodydiagram
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Dynamicsofrigidbodies,page3
• Drawforeachspool:• anextendedfree-bodydiagram• a(point)free-bodydiagram
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Dynamicsofrigidbodies,page3
• Whatwouldeachstudentonthepreviouspagepredict?
1. Theyhavethesamemassandsamenetforcesothecentersofmasshavethesameacceleration.Thetensionshavethesameeffectontranslationalmotion.
2. Sometensionisusedtorotatethespool.Whenaforcecausesrotation,ithaslesseffectontranslation.
3. Iwasthinkingaboutenergy.Theyhavethesametotalkineticenergyatthefinishline.SincethespoolhassomerotationalKE,itmusthavelesstranslationalKE.
Threedifferentpredictions
Sameforces,samemassà AlandsatsametimeasB
ThaslesseffectonAsoAhaslargernetforcedownà AlandsbeforeB
Sametotalenergy,Ahasrotationalandkineticà AlandsafterB
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Spoolsconnectedby
string
Dynamicsofrigidbodies,page4
F.Supposeyouwanttoconsiderhowaforceaffectsthetranslationalmotionofthecenterofmassofanobject.Shouldyouconsider:
• whereontheobjecttheforceisexerted?
• howtheforceisaffectingtherotationalmotionoftheobject?
IntheTutorialhomework, studentsreconciletheirresultswithworkandenergy
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Assessmentsofstudentlearning
• "Pretests"• Questionsadministeredafterallinstructionthroughlectureandtextbookbutbeforestudentshadworkedthroughtutorial.• Providemotivationforthetutorialsandinsightsintostudentreasoningthatguideddevelopment
• "Post-tests"• QuestionsadministeredafterallinstructionincludingTutorialandTutorialHomework.Typicallysomewhatmoredifficultthanpretests.
Note:Resultsaretypicallywithinabout5%fromclasstoclass,independentofinstructorortextbook.
Thus,resultsfrommultipleclassesarecombined.
"StudentunderstandingoftheapplicationofNewton‘ssecondlawtorotatingrigidbodies,”H.G.Close,L.S.Ortiz,andP.R.L.Heron,Am.J.Phys. 81 (6)2013 32
ExamplesofPretests
• Studentsaskedtocomparecenter-of-massaccelerations(directionsandmagnitudes)oftheblocksorpucksattheinstantsshown.
• StudentsaskedabouttheorderinwhichtheobjectswouldcrosstheFinishline.
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ResultsfromPretests
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Pucks Block-and-spool
Correct(equalacceleration/sametime) 20% ~5%Treatingaforceashavinglesseffectontranslation ifitalsoresultsinarotation 65% 60%
Beliefthataforceappliedattheedgeofanobjectcausesonlyrotation N/A 20%
Analysisofresultsguideddesignoftutorialoverseveralyears
• Version1:o ‘Unconnectedspools’o Studentdialogue(butwithouthavingstudentsapplyeachstudent’sreasoningtonewcase)
Someimprovement:From20%to40%correct
• Versions2&is3ledtosmallgainsoResults,however,indicatedstudentsheldverystronglytotheideathattheeffectofaforceontranslationisdecreasediftheforcealsocausesrotation.
oNote:Theycanbelievethisandstillanswerthe‘unconnectedspools’questioncorrectly.
• Version4:The‘connectedspools’experimentwasdevelopedtotargetthisideadirectly(sincetheforcesonbothspoolsarethesame).
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ResultsfromPost-tests
Pucks Block-and-spool
Pretest Post-test Pretest Post-test
Correct(Equalacceleration/sametime) 20% 70% 5% 80%
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Practical criterion for effectiveness of a tutorial:
Post-test performance of introductory studentsmatches (or surpasses)
pretest performance of graduate students.
(TAswereabout30%correctoncircularpucksquestion)
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Generalizationbasedonfindingsfromresearch:
Itisinsufficientfortheinstructorto
• giveclearexplanations
• showdemonstrations
• assignproblemsandprovidesolutions
• beinformedaboutstudentdifficulties
Activementalengagementbythestudents,themselves,isnecessary.
On qualitative problems:
• much better
Onquantitativeproblems(e.g.,endofchapter):– typicallysomewhatbetter
– sometimesmuchbetter
Effectoftutorialsonstudentperformance
Assessments of student learning at UW and beyond on many topics
despite less time devoted to solving standard problems
Onretention:– sometimesmuchbetter
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The tutorials are one example of how, with a small time allotment, a research-based curriculum can help:
•make physics meaningful to students
• provide a foundation for quantitative problem solving
• develop scientific reasoning ability
evenunderconstraintsoflargeclasssize,breadthofcoverage,fastpace,limitedtime
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The perspective that teaching is a science, as well as an art, is an effective approach for:
• setting high (yet realistic) standards
• assessing the extent to which meaningful learning takes place
• helping students meet expectations
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