On time to the doctorate : a study of the lengthening time to completion for doctorates in science and engineering

188 Pages·1990·0.966 MB·English

by  coll.

ee
us i
s are trd. Plea
ke
eaert
Page brally ins OOOOnnnn TTTTiiiimmmmeeee ttttoooo tttthhhheeee DDDDooooccccttttoooorrrraaaatttteeee
s. ent
ed
al typesetting filhave been acci A Study of the Increased TimEen tgoi nCeoemrinpglete Doctorates in Science and
ginay
orim
he ors
m terr
ot frophic Howard Tuckman
na
er book, me typogr SYusuapnin C Boayele
p
ao
ps
original ed, and
he ain
m tret
oe
ated frnnot b
ea
es crer, c
L filwev
Mo
Xh
m g,
ed fromattin
en recomposg-specific forn.
eno
ation of the original work has bding styles, and other typesettiauthoritative version for attributi
epresentaks, hean as the
digital rord breblicatio
PDF file: This new nal; line lengths, wnt version of this pu NATIWOaNsAhiLng AtoCnA, DD.ECM. 1Y9 9P0RESS
About this to the origiuse the pri
ee
us ii
s are trd. Plea
es. Page breakdentally inserte NbTmehOirtestT e saTTIeurC hhercvEie osde :n Nr yrsTae aiwphpstrtieonioo nr pnjftge rrahco oloat mj Afesi sc mcbt thape etdeaehm ernactm b toro eeuiyfsrvn s toitc hehofiew elfSs pe tscohrudiofee b bg ntjNhyercaec eaam tstN i ogo ioasfrn otftaai uhot lph pinAsre a oi rclvOfe aaA ppdftfoeceeir,armc tsdne oywe oon mnaofsps fy S o rSa ocotphciffepiie etSnrr,no tctsicvhifeeeiealcnsfdn ,-c a pbtetnhhesydree, p t tENahehuenteaut g tGhNaiiootnoainrenvt aieageolrc r insAcnnoaoigcnclr aidgAPedi etcBneyramgso do oaytefnor mddon p ifeyosr l Eotf oi (cnntOfhe ggEdeSiun unEiNesrgPeheai)snret.i iedaone pngsrpa,ci nrlha ognoRv,dl eaea srdtnehs d abee r ytncIh nghaesa RCtIginteeousdputt oienit rncuoti t fsleR ,c M ewoievfehn iMdeotiiwsfceeii dc nCm ieaco.neimnmde--.
esetting filbeen acci etahnnedg ictnheTeacherhertnie nNircg gaa trrli eaomsnnetaaeatldrt ec Atrhosc, . ai dDtd eberdym.i c Ftyahr taeoen fdCk E toPonn rggtehirsneese s feisusr iripntnhr g1ee s8rwia6dan3esc,n eett hs ootefaf Abstclhciiesaeh dnNeecdamet iiaynon nh1daa9 lts6 e Aa4c c,hm aundanoendlomdegary ytt e hoa tefnh Sdcahc tt iaoreer nttqehcuree iisorr.ef u st shiete t foNo raa tdtihvoeins agele tnAheecr aafdel dewmeeryalfl a ogrfeo S.v cUeirepnnomcnee tsnh,t e ao san ua st hpcoiaerrniattlyilfe iolcf
al typhave oArcgaadneizmayti oonf Socf ioeuntcsetas nthdein rge sepnogninsiebeirlsit. yI tf oisr aaudtvoinsoinmgo tuhse ifne ditesr aald gmoivneisrtnrmateionnt. aTnhde i Nn athtieo nsealle Actcioand eomf yit so fm Eenmgbinerese,r isnhga rainlsgo wspitohn tshoer sN eantgioinneaelr-
originmay iDnrg. pRroobgerratm Ms .a Wimheidte a its m theee tpinregs indaetniot noafl tnheee Ndsa,t ieonncaolu Aracgaedse emdyu coaft iEonng ainnede rreinsega.rch, and recognizes the superior achievements of engineers.
he ors approTphreia Iten sptritouftees soifo Mnse idni cthinee e wxaams einsatatibolnis hoef dp oinli c1y9 7m0a bttye rtsh ep eNrtaatiinoinnagl tAoc tahdee hmeya lothf Sofc itehnec peus btoli cs.e Tcuhree Itnhset istuertev iaccetss oufn edmeri ntheen tr emsepmonbseirbsi loitfy
m terr given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initia-
ot frophic tive, Ttoh ied Nenattiifoyn iasls uReess eoaf rmche dCiocauln ccailr ew, arse soeragracnhi,z aendd b eyd tuhcea Ntioanti.o Dnar.l SAacmadueeml Oy .o Tf hSiceire insc pesre isni d1e9n1t6 o tfo t haes sIoncsitaittue tteh oe fb Mroeaddi ccionme.munity of sci-
er book, nme typogra edAennaccngaecidn eaee nmwedriyi tnt heog cfg hceSonncmoeilermoanglcu ypen oswi tlaiiiecnthside. tstTh hdehee e AtN eCcraaomtdiuoiennnmceaidyll 'Abiss yc pa autdhdrmeep moiAnsycies asot deofer fEem fdnuy gjr,oit nthihneeeterl iryCni ngobg uyk n inbncoo ipwlt hrhlo eaAvdsi cgdbaeiedn caegonm mdsei eeors vft hiaacende dvsp irttsiohinn ect ghiIp entah sglte ioo tfvupeetederre naormtafi lneM ggno eta,dv gtiehecreninn cmpeyu.e boDnlfti r.cb. F,oF autrhnna dncth tktieh oP enNr iesancstgsiioe iannnnta iadlfc iDcc ora.rn-d
p
ao Robert M. White are the chairman and vice-chairman, respectively, of the National Research Council.
ps
original ed, and PsaRriAly-T 8rh7eif1sl9 er8cet5p 5toh.r etO ivspi iebnwaiso eondfs ,to hfnien rsdepisnoegnassr,co hcrio ncngocn laudgsueicnotcneisde, sbo.yr rOeScoEmP,m weintdha tthioen ssu epxpporret sosfe dth ien N thaitsio pnuabl lSiccaiteinocne a Freo uthnodsaet ioofn ,t huen dauerth NorSsF a Cndo ndtora ncot tN noe.ces-
he ain Library of Congress Catalog Card No. 89-62949
m tret International Standard Book Number 0-309-04085-X
oe Additional copies of this report are available from : National Academy Press 2101 Constitution Avenue, N.W. Washington, D.C. 20418
ated frnnot b SP0ri1n0ted in the United States of America
ea
es crer, c
L filwev
Mo
Xh
m g,
ed fromattin
en recomposg-specific forn.
eno
ation of the original work has bding styles, and other typesettiauthoritative version for attributi
epresentaks, hean as the
digital rord breblicatio
e: This new e lengths, won of this pu
PDF filnal; linnt versi
About this to the origiuse the pri
ee
us PREFACE iii
s are trd. Plea
ke
eaert
ge bry ins Preface
Paall
s. ent
ed
esetting filbeen acci
original typmay have doctoAra tnee.e Ad lethxoisutsg hf otri mbeet tteor tmheo ddeolcst oorfa wteh haat sc obneternib suttueds iteod cbhya nAgbeesd iin atnhde tBimenek tihna (t1 s9tu8d7e),n Btse traeklseo tno (c1o9m6p0l)e, tPe rtihoer
he ors (1962), and Wilson (1965), none of these studies are based on a causal model of student decisionmaking, and
m terr none consider the role of market forces in student decisions. The data presented in Chapter 1 suggest that time to
not froaphic tthweo dyoecatrosr.a Fteu irnth secrmienocree, aint dis eanngtiinceipearitnedg tfhiealtd tsh he alse nbgetehne nleinngg tthreennidn gw sililn cpee r1s9is6t,7 —at ilne assot minet of itehlde sn, ebayr afus tmuruec, ha nads
er book, me typogr hearxaevp eeli ckuteenldfy o irtnot u tnbhaeetc eno umcmoenb sienercq rouefea njsocinbegs o lybp eeccnoainuncsgeesr noinef dtt hhwee i atdhce aciddlieenmnet iicifny s ietnhcget o acrn odiln le utgnhede-e a1rgs9et9a 0npsdo.ip nIugnl awrteiaosypnso antnosde a, tuphguemb dleirnca tm ptohalteii ccsy ui npmcparleyka eosresf
p
ao
ps new doctorates. While shortages of this type are not expected for a few years, it is useful now to determine
original ed, and wanhde tehnegr ipnoeelirciinegs cfiaenld bse. Eadxoispttiendg tshtautd cieasn dliom nito ot rp rreovveirdsee tthhee tirnefnodrm toawtioanrd n leoendgeedr cboym ppolleitciyo nm tiamkeerss into t hdee tsecrimenincee
he ain whether public policy could, or should, alter completion times sufficiently to slow or reverse the trends discussed
m tret in Chapter 1, or whether any policies can have a major impact on supply in the impacted fields.
oe
ated frnnot b timesT shien cpeu r1p9o6s7e,s toof pthroev pidrees ean tt imstue-dsye raieres tdoa trae nbdaesre afno ri nt-hdee pptehr iaonda l1y9s6is7 –o1f 9w8h6a, ta hnads thoa pdpeveneleodp toa cmoomdpelle ttihoant
ea explains some of the factors that have caused an elongation to occur. This study looks at the effects of changes in
es crer, c five types of variables: family background characteristics, student attributes, financial aid, institutional
L filwev environment, and market forces. Using data from the Doctorate Records File and the Survey of Doctorate
Mo Recipients maintained by the Office of Scientific and Engineering Personnel (OSEP) of the National Research
Xh
m g, Council and from other data sources,* the study develops a model to explain changes in both total time to the
ed fromattin doctorate (TTD) and in the
en recomposg-specific forn.
eno
ation of the original work has bding styles, and other typesettiauthoritative version for attributi
epresentaks, hean as the
digital rord breblicatio
e: This new e lengths, won of this pu
PDF filnal; linnt versi Of*fi cAe omf oSrcei ednettiafiilce dan dde Escnrgipintieoenr ionfg tPheer sdoantan eflr.om these sources is available on request from the National Research Council,
About this to the origiuse the pri
ee
us PREFACE iv
s are trd. Plea
eakerte several components of time to the doctorate. The model is then applied to 11 scientific and engineering fields:
ge bry ins ccohmempiustterry ; apnhdy sinicfso ramnadt iaosnt roscnioemncye;s )e;a rethn,g iantemeorisnpgh;e raigcr, icaunldtu mraal risnceie nsccieesn; cebsio; lmogaitchaelm sactiiecnacl essc;i ehnecaelsth ( isnccileundciensg;
s. Paentall psychology; economics; and all other social sciences.
ed This report is organized as follows. Chapter 1 begins with an examination of how and when time to the
esetting filbeen acci dTtiomhcreeto ecr oacetoefm fhipcaoisen nbetense tasn l olloefw nTg TothnDee n atirone g ci,on intlrtloruadsstutrc atetheded, wabnaydy t thihnee w rmihseeica ihnn tvimamleueae ntso T ftoThreD e d afocrchot moarr ae1t 9ep6 rhe7as seto nc th1ea9dn8 ag6ne didn d deiusarcciuhns gso etfhd te.h Iepn e 1ra1ido dfdii,et ialodnnsd,.
al typhave two patterns of change are identified. Finally, quantitative estimates are provided of the person-year losses that
ginay society has incurred from the lengthening of completion time during this period. Chapter 2 reviews five avenues
orim of inquiry in the literature as they relate to time to the doctorate and models of student decisionmaking.
he ors Chapter 3 introduces a causal model of the determinants of TTD based on an opportunity-cost framework of
m terr student decisionmaking. The role of financial aid and of market forces is explored in this context. Chapter 4
ot frophic presents selected data on the zero-order correlations between the independent variables in the model and TTD
er book, nme typogra (vaatatnrrdiiab builtteess s )c aoirsme epxdoainsmecnuintsses)de.d . ,TC hhaean pdtc eotrhr r5ee liacntotironontdrsiu bcuaetmsio otnhn ego sft thaeetia sctshiac laamlr yma joovrda ervli aeabcnltedos r pra(eens.dge .n,u tsnf aeamm sipulylmo mybmaacreykn gto/refom uwpnhdloi cyhamn rdeen gtsr teupsdslaieonnnst
apo coefficients are significant (and of their signs) for alternative specifications of the model. Several variants of the
ps
original ed, and rtmhegeo rddeesels piaeornned icenontetr ofvfdiacuricieaenbdtl set .of o Ferix ntphalleol yrbe, a Csthihcea mpeftoeferd ce7tls daonisfd ca uslsteesverensr aattlhi veve af rmiinaednaitnssug urse sisinn o gtf h rtiehsg esi stkuteedryye ,dv tathrimeiairbe lietmos .p tChliech aadtpiootcentros ,6r a atpnerd e( sRreeTnstDesa )rt hcahes
he ain questions that warrant further study.
om te ret In addition, an extensive bibliography of readings on the determinants of student decisionmaking is
ated frnnot b p(2ro) vtihdee dp (eprspo. n1-0y7e–a1r 1l1o)s.s Aesp preesnudlitxin Ag (fpropm. 1 1a3 –le1n7g3t)h penroinvgid eosf aTdTdiDti,o n(a3l) tavbalreias balbeos uitn ( 1t)h eth em coodmelp, o(n4e)n tzse orof -TorTdDer,
ea
es crer, c ctiomrree ltaot idooncs toarmatoen gfo trh teh ein pdoeppeunladteionnt vaas riaa bwlehso, le(5 a) nsde vfeorra sl eeleqcutaetdio dnes mfoorg reasptihmica tginrogu TpsT. DF,i naanldly ,( 6a)c rmonedyimans utosteadl
L filwev throughout this report are listed in Appendix B (pp. 175–177).
Mo
Xh Staff
m g,
ed fromattin HOWARD TUCKMAN, CONSULTANT
en recomposg-specific forn. YSLUIUNSPDAINAN BSC.A ODEYI,X LR,E EE,S DSETIATAROFCRFH O AFFSISCOECRIATE
eno
ation of the original work has bding styles, and other typesettiauthoritative version for attributi
epresentaks, hean as the
digital rord breblicatio
e: This new e lengths, won of this pu
PDF filnal; linnt versi
About this to the origiuse the pri
ee
us CONTENTS v
s are trd. Plea
ke
eaert
ge bry ins Contents
Paall
s. ent
ed
esetting filbeen acci
al typhave
originmay Executive Summary 1
he ors Findings 1
m terr Conclusions 4
not froaphic 1 What has been Happening to Time to the Doctorate? 7
er book, me typogr ComMThpeeoa nnSe eTnvotestr aaollf T KTiiminmdee st otoo ft htTheei mD Deoocctotorraatete and How They Have Changed Through Time 889
p
ao
ps Mean Time Spent Prior to Graduate School Entrance 12
original ed, and MMeeaann TRiemgies tSepreedn tT Aimwea yto f rtohme D thoec tUornaitveersity 1122
he ain Summary 13
m tret The Nature and Significance of the Time Trend 13
oe
ated frnnot b TPahtet eTrnwso o Mf Cohdaenlsge 1134
ea The Shape of Change 19
es crer, c Manpower Loss from Lengthening Total Time to the Doctorate 19
L filwev
Mo 2 Models of the Factors that Affect Student Choice and Time to the Doctorate: A Literature Survey 25
Xh
m g, Literature on Persistence and Attrition 25
en recomposed frog-specific formattinn. LLLSLuiiiittttmeeeerrrrmaaaattttauuuurrrrryeeee oooonnnn EEETdxnTuprDocelaclttmieoden nRatlse Atusrpnisrations 2233389123
eno
ation of the original work has bding styles, and other typesettiauthoritative version for attributi 3 A MTThhoeed eCMl rooitfdi cethalel RDoeltee romf iOnapnptosr otufn TitTyD Costs 333556
epresentaks, hean as the
digital rord breblicatio
e: This new e lengths, won of this pu
PDF filnal; linnt versi
About this to the origiuse the pri
ee
us CONTENTS vi
s are trd. Plea
eakerte Financial Aid and Its Impact on Completion Times 38
ge bry ins TEfhfee cImts poanc tt hoef CToympep oofn eAnitds of TTD 3389
s. Paentall Market Forces and Completion Times 41
ed Effects of Changes in Relative Salaries 41
esetting filbeen acci TheEE Vffffeeaccrittassb oolnfe s Et hUmesp eCldoo ymtomp Deonentve Oenltposp poo ftrh tTueT nMiDtioedsel 444233
al typhave
ginay 4 The Relation Between the Five Vectors of Variables and TTD and its Components: A Comparison 45
orim of Zero-Order Correlations
he ors The Importance of Disaggregation by Field 45
m terr Changes in Family Background Characteristics 46
ot frophic Changes in Student Attributes 46
er book, nme typogra CCChhhaaannngggeeesss iiinnn TMInusaitrtiiktouentti oFannoadrcl FeEsinnvanircoinaml Aenidt 555116
apo Salary Variables 56
ps
original ed, and TThheeE ZSmteporlcook-yO Vmraderneirta bICnloedrircealtaotiro Vn aorfi atbhlee sVectors 666005
he ain Summary 67
m tret
oe
ated frnnot b 5 ChaCnogmesm ionn T VTaDriables Model 6699
ea
es crer, c LWoega kLnineessaer sE oqfu tahteio Cnsommon Variables Model 7711
L filwev Unique Variables Model 71
Mo
Xh Summary of Findings 71
m g,
ed fromattin LWimhaitt aCtiaonn sB oef L theaer Anenda lfyrosims the Findings? 7737
en recomposg-specific forn. 6 ChaERnnegrgeoissll tieendr e Ridne Tgthiismet eUer etnodi v tTehriems iDteyo tcot othraet eDoctorate, Time Prior to Graduate Entrance, and Time not 7799
ation of the original work has beding styles, and other typesettinauthoritative version for attributio TTSuiimmmRREeevmTT aSNDDalpuro yeiiatnnn tEo itttof nhhP nrteerh o ioCUeolfl roe nFt dmthiioqn eim udn GRei ontr ehVnagsed suaV uUrltaiasanrtbeiiav lSbeesclre hsMsio tMyoo ld( oETedlnNetlEr aUUnsc)ien g(T LPinGeEa)r and Log Linear Equations 778888991579
epresentaks, hean as the
digital rord breblicatio
e: This new e lengths, won of this pu
PDF filnal; linnt versi
About this to the origiuse the pri
ee
us CONTENTS vii
s are trd. Plea
ke
eaert
ge bry ins 7 PasWt ahsa Pt rHoalosg Huaeppened to Time to the Doctorate? 9933
s. Paentall Total Time to the Doctorate 93
ed Registered Time to the Doctorate 94
esetting filbeen acci CPoosuVsliadbr lCiea htEiaoxnnpg lAeasnr oianuti nTodnP tGhEe Maneda nTNEU Have Been Large Enough to Explain the Change in TTD? 999567
al typhave Epistemic Explanations 97
ginay Institutional Explanations 97
orim Student Preference-Based Explanations 98
he ors Financial Need-Based Explanations 99
m terr Demographic and Ability-Based Explanations 100
ot frophic Market-Based Explanations 101
er book, nme typogra ImpAIsli cMTahtoeiroreen RsA eo sSfo ianu Cgrcloeen -EItinxntpeulniansngiva Rtei oiDsneo fciontro TrIanTlc DPreraosger ainm TTD? 111000122
apo A Longer Gestation Period 103
ps
original ed, and CILnohcwareneagrs eResd ei tnAu trthtnresi t Afiootnrt rGacratidvueantees sS toufd Aylternative Doctorate Careers 111000455
he ain TTD as a Policy Instrument 105
m tret
oe
ated frnnot b Selected Bibliography 107
ea
es crer, c A ApRpeenladtiexde sTables 111135
L filwev B List of Acronyms 175
Mo
Xh
m g,
ed fromattin List of Tables
en recomposg-specific forn.
eno
ation of the original work has bding styles, and other typesettiauthoritative version for attributi 1111111.......6574123 DEMETEEsshssiaftttte1iiiifx mmmme9Rirm6aaaaee8ttttnuleeeea–cmddddt1ei o9TTTT PBn8iiiiommmmse6thteweeeeinp TTTTet ieBrrrraneeeele nnnn tPFwddddeosssserr siiiieennnnocn na MMMMt-shYteeeee aaaaae Snnnnnader TTRTsv A ioieeLmmrtgcoaatieesluls staNTPTe lRriir omimTeeotd sTereE u TDtntMlootirsi m oeGn,D lag1elrose 9atfucdd8ortr ou7 oeiDmnarsa toU etLce Enteoinnvrgtaerttraehsneictnyeing Total Time to the Doctorate, 1122117822659
digital representord breaks, heablication as the 43444.....41321 CCCCMooooerrrrarrrrneeeellll Taaaattttiiiiimoooonnnne fffftooooorrrr t hPPPAeeeev rrrDecccreeeoannncgtttte oMBH rNlaiaasutrcpemrk,ai e,nbb di1yec,r9 ,P 1 7o1r94fi96 m–D771a4e–9r–p1y81e9 69Sn88do66eunrctse, o1f9 S67u–p1p9o8rt6, 1986 and 1987 4444488077
e: This new e lengths, won of this pu
PDF filnal; linnt versi
About this to the origiuse the pri
ee
us CONTENTS viii
s are trd. Plea
eakerte 4.5 Correlation for Percent Female, 1967–1986 49
ge bry ins 44..67 CCoorrrreellaattiioonn ffoorr APevrecreangte F Arogme aSte Sletacrtitv oef UDnodcetorgraral dPuraotger aSmch, o1o9l6s,7 –11996876–1986 4590
s. Paentall 4.8 Correlation for Percent with Undergraduate Degree in Doctoral Field, 1974–1986 50
ed 4.9 Correlation for Average Tuition Paid 51
esetting filbeen acci 444...111102 CCCooorrrrrreeelllaaatttiiiooonnn fffooorrr PPPeeerrrccceeennnttt wwwiiittthhh PPPrrriiimmmaaarrryyy SSSuuuppppppooorrrttt fffrrrooommm PFRreeidsveearataerlc FhGo Aouvsnesdirasnttmaionentnssht,, i 1p19s96,6 717–9–1619798–8616986 555223
al typhave 4.13 Correlation for Percent with Primary Support from Teaching Assistantships, 1967–1986 53
ginay 4.14 Correlation for Percent with Primary Support from Own Earnings, 1977–1986 54
orim 4.15 Correlation for Percent with Baccalaureate from Foreign Institutions, 1967–1986 54
he ors 4.16 Correlation for Number of Full-Time Equivalent Faculty 55
m terr 4.17 Correlation for Government R&D Spending 55
ot frophic 4.18 Correlation for Percent with Baccalaureate from Category I Research University, 1967–1986 57
er book, nme typogra 44..1290 CCoorr1rr9ee6llaa7tt–iioo1nn9 8ffoo6rr PPeerrcceenntt wwiitthh BGaracdcaulaatuer Deaetger fereo mfro "mT oCpa 4te0g"o Sryc hIo oorl ,C 1a9te6g7o–r1y9 I8I6 Research School, 5578
apo 4.21 Correlation for Percent with Graduate Degree from "Top 40" School, 1967–1986 58
ps
original ed, and 444...222234 CCCooorrrrrreeelllaaatttiiiooonnn Bffooerrt wSAaevleeanrray Sg RAe aLStaiRolAa orTyf IDo afon cRdte oTcraeTtnDets D a1no0dc YtIotesraa Crteso ARmefptceoirnp Deienentgstsree 556990
he ain 4.25 Correlation Between SDR Salaries and Salaries Reported by Other Sources, 1968–1986 61
om te ret 4.26 Correlation for Percent Seeking Postgraduate Employment 62
ated frnnot b 44..2278 CCoorrrreellaattiioonn ffoorr POevrecreanltl wUi.Sth. DUenfeimniptelo Eymmpelnoty Rmaetent or Postdoctoral Appointment 6623
ea
es crer, c 4.29 Correlation for Unemployment Rate of College-Educated Population 63
L filwev
Mo
Xh
m g,
ed fromattin
en recomposg-specific forn.
eno
ation of the original work has bding styles, and other typesettiauthoritative version for attributi
epresentaks, hean as the
digital rord breblicatio
e: This new e lengths, won of this pu
PDF filnal; linnt versi
About this to the origiuse the pri
ee
us CONTENTS ix
s are trd. Plea
eakerte 4.30 Correlation Between Percent Seeking Postgraduate Employment and the Other Market Variables 64
ge bry ins 44..3312 CAomroreulnatt ioofn Afodrj uPsetre dC Vapairtiaa Ntiounm ibne Tr TofD D Eoxcptolarianteesd ibny t hEea cUhn oitfe dth Se tFatievse, V19e6ct7o–r1s986 6645
s. Paentall 4.33 Number of Fields in Which Each Variable Had a Statistically Significant Correlation with TTD or 66
ed RTD
esetting filbeen acci 555...312 SSSuuummmmmmaaarrryyy ooofff CCUoonmmiqmmueoo Vnn aLLrioinageb-aLleri snM Meoaord deMle loR Rdeegelgr Rerseessgisorieonsn Rs iReosenus Rultlset ssf uoflort rsT TfToTDrD T, ,bT byDy V, Fbairyei laVdbaleriable 777024
al typhave 5.4 Number of Fields in Which Variable Has Statistically Significant Effect on TTD 76
ginay 6.1 Summary of Common Linear Model Regression Results for RTD, by Field 80
orim 6.2 Summary of Common Log-Linear Model Regression Results for RTD, by Field 81
he ors 6.3 Summary of Unique Variables Model Regression Results for RTD, by Field 82
m terr 6.4 Number of Fields in Which Variable Has Statistically Significant Effect of TTD 84
ot frophic 6.5 Summary of Common Linear Model Regression Results for TPGE, by Variable 86
er book, nme typogra 666...678 SSSuuummmmmmaaarrryyy ooofff CCCooommmmmmooonnn LLLoiongge--aLLrii nnMeeoaarrd eMMl ooRddeeegllr RReseesggiorreenss Rssiieoosnnu RRltsee ssfuuollrtt ssT ffNooErr TTUPN, GbEyEU V,, bbayryi VaFbailerelidab 9l0e 88 89
apo 7.1 Median Total Time to the Doctorate Over Time 94
ps
original ed, and List of Figures
he ain
m tret
oe
ated frnnot b
ea
es crer, c
L filwev 1 Median years to the doctorate, all fields combined including humanities and education fields, 1958–1986 7
XMho 2 Components of mean total years to the doctorate, by field, 1967 and 1986 10
m g, 3 Mean total time to the doctorate, by field, 1967–1986 20
ed fromattin
en recomposg-specific forn.
eno
ation of the original work has bding styles, and other typesettiauthoritative version for attributi
epresentaks, hean as the
digital rord breblicatio
e: This new e lengths, won of this pu
PDF filnal; linnt versi
About this to the origiuse the pri