research in physics education: a resource for improving ...€¦ · research in physics education:...

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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