How do Incentives affect Creativity? - Universität Erfurt · liehst lieht lies liest lila lisa...
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How do Incentives affect Creativity? Katharina Eckartz and Oliver Kirchkamp and Daniel Schunk Universit¨ at Jena 7. Mai 2011
Transcript of How do Incentives affect Creativity? - Universität Erfurt · liehst lieht lies liest lila lisa...
How do Incentives affect Creativity?
Katharina Eckartz and Oliver Kirchkamp and Daniel Schunk
Universitat Jena
7. Mai 2011
Incentives and Creativity — Beispiel
The candle problem (Karl Duncker, 1945)
I eine Kerze
I eine Kiste Reißnagel
I ein Streichholzbriefchen
Aufgabe: “die Kerze muss so an der Wand anbracht werden, dasssie nicht auf den Tisch tropft”
→
“functional fixedness”: Anreize machen Versuchspersonenlangsamer.
Andere kontroproduktive Anreize
I Camerer, Babcock, Loewenstein and Thaler (1997): Taxifahrer→ earnings target
I Dandy, Brewer and Tottman (2001): Freiwurfe vonBasketballspielern beim Training / beim Spiel.→ pressure produces choking
I Ariely, Gneezy, Loewenstein, Mazar (2009):I packing quarters (+ 5 weitere Aufgaben, die nichts mit
Kreativitat zu tun haben)
Anreiz: niedrig mittel hoch≈3 Stunden Lohne ≈3 Tagelohne ≈1 Monatslohn
Anteil “sehr gut”: 25.0% 33.3% 0%
Anreize und Kretivitat
→ Vergleiche within subject verschiedene Anreizsysteme.
Wir suchen eine Aufgabe mit den folgenden Eigenschaften:
I Kreativitat zur Losung der Aufgabe erforderlich (untypisch furreal-effort tasks im Labor)
I “Qualitat” der Losung ist leicht messbar
I Aufgabe bleibt bei Wiederholung interessant (klappt nicht mitdem candle problem)
Damit kann man
I within subject
I mit sehr ahnlichen Aufgaben
I verschiedene Anreizsysteme vergleichen
Task 1:
Gegeben die folgenden 12 Buchstaben
accehhikllst
Erzeugen Sie innerhalb von 5 Minuten Worter mit so vielenPunkten wie moglich:
I 1 fur den 1. Buchstaben eines Wortes
I 2 fur den 2. Buchstaben eines Wortes
I 3 fur den 3. Buchstaben eines Wortes
I...
z.B.:
ei 1+2=3 Punktetal 1+2+3=6 Punkte...schickt 1+2+3+4+5+6+7=28 Punkteschachtel 1+2+3+4+5+6+7+8+9=45 Punkteschalkheit 1+2+3+4+5+6+7+8+9+10=55 Punkte
Was ist Kreativitat?
I Kreativitat = etwas “neues” finden
I Wie funktionieren kreative Innovationen:
Ideen werden generiert und gegen unser Modell der Naturgetestet.
I Wie funktioniert die Worteraufgabe:Worter werden generiert und gegen unser Modell von Sprachegetestet.
I In beiden Fallen ist “das Neue” bereits vorhanden —Kreativitat ist die Abkurzung zur Entdeckung des Neuen
Ein deutsches 75%-Quantil LettersetBuchstaben Punkte Worter Ahnlichkeit
accehhikllst 5585 330 0.888436ach achilles achse achsel acht achte achteck achtecks achtel achtes achtle ahle ai aktakte aktie akts alice alices all all alle alles alls als alt alte altes asche asket ast at ca cachecaches call calls cellist ch chalet chalets chate chi chic chice chices chicste chile cia echteh eilst eilt eis eiskalt eklat elch elchs eli elias elis es esc et etc eth ethik ethisch hackehackst hackt hackte hai haie haies hais hake hakst hakt hakte hall halle halls hallst hallthallte hals halt halte hasche hascht haschte hase haskell hast haste hat he hecht hechtsheck hecklicht hecklichts hecks heckst heckt hehl hehlst hehlt heil heilst heilt hektischhell hellst hellt hielt hit ich ist it kachel kahl kahle kahles kahlheit kai kais kali kalis kaltkalte kaltes kastell keil keils keilst keilt kelch kelchs kiel kiels kies kille killst killt killtekiste kit kits kitsch klatsch klatsche kleist kt lach lache lachs lachse lachst lacht lachtelack lacke lackes lacks laiche laichst laicht laichte laie las lasche last laste latsche leastlech lechs leck lecks leckst leckt leica leicht leihst leiht leis lest licht lichte lichts liehliehst lieht lies liest lila lisa list liste lsi lt sache sachlich sachliche sacht sachte sack sackesackt sackte sah saht saite schach schacht schachtel schah schal schale schalheit schalkschalke schalkheit schall schalle schallt schallte schalt schalte scheck scheich scheit schelltschi schicht schichte schicke schickt schickte schielt schilt schlacht schlachte schlackeschlackt schlackte schlecht schleckt schleicht schlich schlicht schlichte schlick seht seiseicht seil seilt seit sek sekt set sh shell sich sichel sicht sichte sie siech siecht sieh siehtsiel skat sketch ski st stach stachel stachle stack stahl stak stall stck steak steil stichstiche stichel stichle sticke stiel stil stile still stille taille takel takels takle tal tales talktalks tals tasche task teich teichs teil teils tel tick ticke ticks tisch tische
accehhikllst — welche Worter sind korrekt?
german-isowordlist (Heinz Knutzen, 1999, Grundlage fur “ispell”)
enthalt
Formen von Wortern (hascht, hasche, haschte)Namen (auch geographische) (Achilles, Haskell, Lech)Abkurzungen (AI, CA, ETC)keine Vulgarismen
Wir verwenden Lettersets, die ahnlich in 3 Dimensionen sind:
I Anzahl der erreichbaren “Punkte” ist ahnlich
I Anzahl der erreichbaren Worter ist ahnlich
I Ahnlichkeit der Worter ist ahnlich (hier verwenden wirfstrcmp aus GNU Gettext 0.17 um fur jedes WortAhnlichkeit zum ahnlichsten Wort in der Menge zu berechnen)
Wir haben 100 000 Lettersets erzeugt, berechnen moglich Worter,Punkte, und Ahnlichkeit und bestimmen eine kleine Gruppeahnlicher Mengen.
Deutsche lettersets
letters points words similarity within
aceehhinrssa 5501 323 0.886879cdehhlorsstt 5445 323 0.886458aehklllprstt 5386 326 0.886948aeeeggllmnru 5430 323 0.886883deehhimnnprt 5449 321 0.886626aaeehhiknstt 5503 329 0.886679cdeeillrsstw 5427 327 0.887130deegilmnnpuw 5405 322 0.887139
I In allen Dimensionen (Punkte, Worter, Ahnlichkeit) sind dieseMengen im gleichen 2% Perzentil der ursprunglichen Gruppevon 100 000 Mengen.
I Wir verwenden diese 8 Mengen in unserem Pilot und streichendie zwei Mengen, die im Pilot am besten und die zweiMengen, die im Pilot am schlechtesten abschneiden.
I Wir verwenden nur noch die 4 Lettersets in der Mitte.
Task 2: Kreativitat / Intelligenz
Task aus einem Standard IQ-Test (Raven’s Advanced ProgressiveMatrices, set II, Aufgaben sind angemessen fur Erwachsene undHeranwachsende mit uberdurchschnittlicher Intelligenz)
Im Gegensatz zur Worteraufgabe. . . :
I Worteraufgabe misst Kreativitat
I Raven’s Matrizen messen ‘eductive ability’ (Struktur inKomplexitat finden) und ‘reproductive ability’ (Informationenspeichern und reproduzieren).
Design: within subject
I Jede Versuchspersonen erfahrt 3 AnreizmechanismenI flat: 10¤I linear: 0.04¤ / Wort-Punkt (1.60¤ / pro Raven Matrix)I tournament: 20¤ fur Gewinner, 5¤ fur 3 Verlierer
I Wir verwenden alle 6 Reihenfolgen der Anreize furunterschiedliche Versuchspersonen:
flat → linear → tournamentflat → tournament → linear
linear → tournament → flatlinear → flat → tournament
tournament → flat → lineartournament → linear → flat
Design: within subject
stage letterset flat linear tournament
1 aceehhinrssa 56 55 552 Picture 1,4,7,... 56 55 55
3 aeeeggllmnru 55 53 584 Picture 2,5,8,... 55 53 58
5 deehhimnnprt 55 58 536 Picture 3,6,9,... 55 58 53
7 aaeehhiknstt 70 51 45
I Lettersets und Pictures (Raven Matrizen) kommen stets ingleicher Reihenfolge.
I Wir konnen nicht zwischen Lernen und spezifischer Aufgabeunterscheiden (dafur interessieren wir uns auch nicht).
I Wir konnen zwischen Aufgabe und Anreizmechanismusunterscheiden.
Versuchspersonen
166 Versuchspersonen.
males per session
Per
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of T
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20 25 30
I Geschlecht ist in jeder Session ausgewogen (wichtig furTournaments)
Pictures (eductive ability) ↔ Words (creativity)
Korrelation der Leistung in verschiedenen Tasks (95%Konfidenzintervall, basierend auf ABC Bootstrap)
pictures/pictures
words/pictures
words/words
0.2 0.3 0.4 0.5 0.6 0.7
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●
→ Worter und Bilder scheinen unterschiedliche Fahigkeiten zumessen.
Funktionieren Anreize? Relative Effektgroße:Was erklart Leistung?
I subject: Individuelle Fahigkeit der Versuchsperson?
I stage: Erfahrung (Stufe im Experiment)?
I incentive: Anreize?
Performance =∑
Subjects
βsubj.dsubj.+∑Stages
γst.dst.+∑
Incentives
dinc.δinc.+εi
durchschnittlicher Beitrag zum R2 in % (Lindeman, Merenda andGold, 1980)
Words Pictures
subject 68.61 67.27stage 6.60 2.74
incentive 0.44 0.22
→ Der (aggregierte) Einfluss von Anreizen ist sehr klein!
Individuelle Reaktion auf Anreize εsubj.,inc. (Worter)
Wordp. =∑
Incentives
(βinc. · dinc.
)+
∑Stages
βst. · dst. + εsubj.,inc.︸ ︷︷ ︸reactive toincentives
tournament
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r = 0.590[0.456, 0.687]
r = −0.526[−0.626,−0.398]
r = −0.430[−0.555,−0.264]
I Wer auf Tournaments reagiert, reagiert auch auf lineareAnreize
I Qualifizierte Versuchspersonen werden durch Anreizeentmutigt
(95% Konfidenzintervalle basieren auf dem ABC bootstrap)
Individuelle Reaktion auf Anreize εsubj.,inc. (Bilder)
Pictp. =∑
Incentives
(βinc. · dinc.) +∑Stages
βst. · dst. + εsubj.,inc.
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r = 0.589[0.461, 0.701]
r = −0.523[−0.630,−0.405]
r = −0.506[−0.620,−0.372]
I Wer auf Tournaments reagiert, reagiert auch auf lineareAnreize
I Qualifizierte Versuchspersonen reagieren weniger auf Anreize
(95% Konfidenzintervalle basieren auf dem ABC bootstrap)
Anreizwirksamkeit ist Aufgabenspezifisch
linear.pict
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Einfluss von Anreizen auf Wortlange und Originalitat:
Wortlangeaccehhikllst: ach, akt, all, als, alt, eis, ich, ist,. . .
cellist, eiskalt, hecklicht,. . .
Length =∑
Subjects
βsubj.dsubj. +∑Stages
γst.dst. +∑
Incentives
dinc.δinc. + εi
Ahnlichkeit / Jaro-Winkler Distanzaccehhikllst: hall halle halls hallst hallt hallte,. . .
achse, eilst, kitsch, licht, seicht,. . .
Distance =∑
Subjects
βsubj.dsubj. +∑Stages
γst.dst. +∑
Incentives
dinc.δinc. + εi
durchschnittlicher Beitrag zum R2 in % (Lindeman, Merenda andGold, 1980)
Words Picture Length Distance
subject 68.61 67.27 57.11 5.24stage 6.60 2.74 0.16 1.71
incentive 0.44 0.22 0.66 0.02→ Der (aggregierte) Einfluss von Anreizen ist sehr klein!
Zusammenfassung
I “Kreative Leistung hangt von Individuen ab und nicht vonAnreizen” (jedenfalls im Aggregat)
I Kein aggregierter Effekt von Anreizen aufI KreativitatI Leistung im IntelligenztestI FehlerI GeschwindigkeitI Originalitat
I Effekte auf Mikroebene:I Wirksamkeit verschiedener Anreize (tournament/linear) ist
positiv korreliert (fur die gleiche Aufgabe)I Gute Arbeiter werden durch Anreizen entmutigtI Anreize sind Aufgaben-spezifisch
Effect of incentives on words:
Wordp. = β0 +∑
Incent.
βinc. · dinc. +∑Stages
βst. · dst. + εsubj. + εsubj.,t
(“flat” is the baseline)
β σ t p value 95% conf interval
(Intercept) 219 9.72 22.5 0.0000 200 238linear 11.4 10 1.14 0.2555 -8.32 31.2tournament 18.2 10.1 1.81 0.0709 -1.56 38stage3 7.21 10 0.72 0.4718 -12.5 26.9stage5 64.5 9.99 6.46 0.0000 44.8 84.1
→ no significant treatment effect on the aggregate level
Effect of incentives on pictures:
Pictp. = β0 +∑
Incentives
βinc. · dinc. +∑Stages
βst. · dst. + εsubj. + εsubj.,t
(“flat” is the baseline)
β σ t p value 95% conf interval
(Intercept) 5.68 0.187 30.4 0.0000 5.32 6.05linear 0.14 0.187 0.749 0.4545 -0.228 0.508tournament 0.231 0.2 1.15 0.2495 -0.163 0.624stage4 0.708 0.191 3.7 0.0003 0.332 1.09stage6 0.717 0.19 3.78 0.0002 0.344 1.09
→ no significant treatment effect on the aggregate level
Einfluss von Anreizen auf Wortlange:
Length = β0 +∑
Incentives
βinc. · dinc. +∑Stages
βst. · dst. + εsubj. + εsubj.,t
β σ t p value 95% conf interval
(Intercept) 4.29 0.0391 110 0.0000 4.21 4.37linear 0.081 0.0419 1.93 0.0543 -0.0015 0.164tournament 0.0266 0.0451 0.59 0.5556 -0.0621 0.115stage3 0.0062 0.0424 0.146 0.8837 -0.0772 0.0896stage5 0.0375 0.0417 0.899 0.3694 -0.0446 0.12
→ Kein signifikanter Einfluss auf Wortlange
Effect of incentives on innovativeness for single tasks:
Distance to the previous word is measured as Jarowinkler
Distance = β0+∑
Incentives
βinc. ·dinc.+∑Stages
βst. ·dst.+εsubj.+εsubj.,t
β σ t p value 95% conf interval
(Intercept) 0.557 0.00764 72.9 0.0000 0.542 0.572linear 0.00457 0.00569 0.804 0.4217 -0.00658 0.0157tournament 0.00704 0.00584 1.2 0.2282 -0.00441 0.0185stage3 0.0176 0.00713 2.47 0.0136 0.00362 0.0316stage5 0.109 0.00692 15.7 0.0000 0.0955 0.123stage7 0.0558 0.00706 7.9 0.0000 0.0419 0.0696
Participants-II
other2
other1
span
lat
fr
en
de
Language competence (none/native)
0 50 100 150
scrabble
crossw
logic
creative
discuss
read
Hobbys (never/a lot)
0 50 100 150
Attitudes towards risk
0 1 2 3 4 5 6 7 8 9
0=risk averse, 10=risk loving
05
1015
2025
3035
Perceived difficulty and joy
difficulty: 0=easy .. 5=hard
words
pict
ures
0 1 2 3 4 5
0123
45
joy: 0=none .. 5=lots
words
pict
ures
0 1 2 3 4 5
0123 45
χ225 = 34.0833, p = 0.1061 χ225 = 224.724, p = 0.0000
Effect of incentives on mistakes with words:
Correct = β0 +∑
Incentives
βinc. · dinc. +∑Stages
βst. · dst. + εsubj. + εsubj.,t
β σ t p value 95% conf interval
(Intercept) 0.775 0.0113 68.6 0.0000 0.753 0.797linear -0.00899 0.0125 -0.721 0.4713 -0.0335 0.0155tournament 0.00243 0.0124 0.196 0.8445 -0.0219 0.0267stage3 0.0051 0.0121 0.421 0.6739 -0.0187 0.0289stage5 0.0453 0.0128 3.52 0.0005 0.02 0.0705
→ incentives do not reduce the number of mistakes with words
Effect of incentives on mistakes with pictures:
Correct = β0 +∑
Incentives
βinc. · dinc. +∑Stages
βst. · dst. + εsubj. + εsubj.,t
β σ t p value 95% conf interval
(Intercept) 0.602 0.0187 32.3 0.0000 0.565 0.639linear 0.00109 0.019 0.0572 0.9544 -0.0364 0.0386tournament 0.0123 0.019 0.646 0.5187 -0.0252 0.0498stage4 0.0558 0.0199 2.8 0.0054 0.0166 0.095stage6 0.0393 0.0191 2.05 0.0411 0.00159 0.0769
→ incentives do not reduce the number of mistakes with pictures
Time to find new words
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0 3 6 10 15 21 28 36 45
0.5
2.0
5.0
20.0
100.
0
Wordpoints
Tim
e [S
econ
ds]
→ incentives do not affect “innovativeness” (measured as distancebetween successive words)
Effect of incentives on time/word:
Time/Word = β0+∑
Incentives
βinc.·dinc.+∑Stages
βst.·dst.+εsubj.+εsubj.,t
β σ t p value 95% conf interval
(Intercept) 13.5 0.347 39 0.0000 12.8 14.2linear -0.0914 0.184 -0.498 0.6187 -0.451 0.268tournament -0.342 0.186 -1.84 0.0660 -0.708 0.0226stage3 -0.401 0.222 -1.8 0.0714 -0.837 0.035stage5 -1.88 0.209 -9.02 0.0000 -2.29 -1.47stage7 -1.51 0.212 -7.11 0.0000 -1.92 -1.09
→ incentives do not make people work significantly faster
Self selection of incentives and εsubj.,inc.
selection of incentives, conditional on past performance
average performance
self_
sele
ctio
n
−100 0 100 200 300
flat
linea
r
0.0
0.2
0.4
0.6
0.8
1.0
Self selection of incentives and εsubj.,inc.
P(flat) = Φ(β0 + β1〈averagePerformance〉)
Estimate Std. Error z value Pr(>|z|)
(Intercept) -0.2076 0.0997 -2.08 0.0372avPerform -0.0032 0.0011 -2.78 0.0054
