Exploring the relationship between knowledge and anchoring effects

122 Pages·2017·1.09 MB·English

University of Iowa
Iowa Research Online
Theses and Dissertations
Summer 2011
Exploring the relationship between knowledge and
anchoring effects: is the type of knowledge
important?
Andrew Robert Smith
University of Iowa
Copyright 2011 Andrew Robert Smith
This dissertation is available at Iowa Research Online: https://ir.uiowa.edu/etd/1264
Recommended Citation
Smith, Andrew Robert. "Exploring the relationship between knowledge and anchoring effects: is the type of knowledge important?."
PhD (Doctor of Philosophy) thesis, University of Iowa, 2011.
https://doi.org/10.17077/etd.tmqlcjfp
Follow this and additional works at:https://ir.uiowa.edu/etd
Part of thePsychology Commons
EXPLORING THE RELATIONSHIP BETWEEN KNOWLEDGE AND ANCHORING
EFFECTS: IS THE TYPE OF KNOWLEDGE IMPORTANT?
by
Andrew Robert Smith
An Abstract
Of a thesis submitted in partial fulfillment
of the requirements for the Doctor of
Philosophy degree in Psychology
in the Graduate College of
The University of Iowa
1
July 2011
Thesis Supervisor: Professor Paul D. Windschitl
1
ABSTRACT
Numeric estimates are influenced by a variety of factors including a person’s
knowledge and the presence of numeric anchors. In general, greater knowledge leads to
more accurate estimates and the presence of anchors decreases accuracy. This
dissertation is focused on the relationship between these two factors. At an intuitive
level, it seems that increased knowledge should lead to a decrease in anchoring effects.
Unfortunately, the research on knowledge and anchoring is quite mixed. This
dissertation describes four studies—the first three were experimental and the last was
correlational—that addressed two primary questions: 1) Does knowledge level moderate
anchoring effects such that greater knowledge in a domain is associated with smaller
anchoring effects? 2) Does this relationship depend on the type of knowledge one has?
Studies 1 and 2 provided an answer to the first question. In Study 1, participants who
studied a list of country populations—i.e., high knowledge participants—were less
influenced by anchors than participants who learned irrelevant information. In Study 2,
those participants who studied a list of new car prices were less influenced by anchors
than participants who learned irrelevant information. In Study 3, participants learned
information designed to influence different types of knowledge. The results of Study 3
supported the prediction that only those participants in conditions that increased metric
knowledge—and not mapping knowledge—would exhibit reduced anchoring effects.
1

Finally, in Study 4, participants’ knowledge was measured and compared to their
anchoring effects. Contrary to expectations, none of the knowledge measures were
related to the participants’ anchoring effects. Theoretical and practical implications, as
well as reasons why the last study was not consistent with the first three, are discussed.
Taken together, these studies indicate that both the amount and type of knowledge one
has are important in determining one’s susceptibility to anchoring effects.
2
Abstract Approved: ____________________________________
Thesis Supervisor
____________________________________
Title and Department
____________________________________
Date

2
EXPLORING THE RELATIONSHIP BETWEEN KNOWLEDGE AND ANCHORING
EFFECTS: IS THE TYPE OF KNOWLEDGE IMPORTANT?
by
Andrew Robert Smith
A thesis submitted in partial fulfillment
of the requirements for the Doctor of
Philosophy degree in Psychology
in the Graduate College of
The University of Iowa
1
July 2011
Thesis Supervisor: Professor Paul D. Windschitl
Graduate College
The University of Iowa
Iowa City, Iowa
CERTIFICATE OF APPROVAL
_______________________
PH.D. THESIS
_______________
This is to certify that the Ph.D. thesis of
Andrew Robert Smith
has been approved by the Examining Committee
for the thesis requirement for the Doctor of Philosophy
degree in Psychology at the July 2011 graduation.
Thesis Committee: ___________________________________
Paul D. Windschitl, Thesis Supervisor
___________________________________
Jason K. Clark
___________________________________
Shaun P. Vecera
___________________________________
Eliot Hazeltine
___________________________________
William M. Hedgcock
To Vanessa
2

ii
ABSTRACT
Numeric estimates are influenced by a variety of factors including a person’s
knowledge and the presence of numeric anchors. In general, greater knowledge leads to
more accurate estimates and the presence of anchors decreases accuracy. This
dissertation is focused on the relationship between these two factors. At an intuitive
level, it seems that increased knowledge should lead to a decrease in anchoring effects.
Unfortunately, the research on knowledge and anchoring is quite mixed. This
dissertation describes four studies—the first three were experimental and the last was
correlational—that addressed two primary questions: 1) Does knowledge level moderate
anchoring effects such that greater knowledge in a domain is associated with smaller
anchoring effects? 2) Does this relationship depend on the type of knowledge one has?
Studies 1 and 2 provided an answer to the first question. In Study 1, participants who
studied a list of country populations—i.e., high knowledge participants—were less
influenced by anchors than participants who learned irrelevant information. In Study 2,
those participants who studied a list of new car prices were less influenced by anchors
than participants who learned irrelevant information. In Study 3, participants learned
information designed to influence different types of knowledge. The results of Study 3
supported the prediction that only those participants in conditions that increased metric
knowledge—and not mapping knowledge—would exhibit reduced anchoring effects.
3

Finally, in Study 4, participants’ knowledge was measured and compared to their
anchoring effects. Contrary to expectations, none of the knowledge measures were
related to the participants’ anchoring effects. Theoretical and practical implications, as
well as reasons why the last study was not consistent with the first three, are discussed.
Taken together, these studies indicate that both the amount and type of knowledge one
has are important in determining one’s susceptibility to anchoring effects.
iii
TABLE OF CONTENTS
LIST OF TABLES ............................................................................................................. vi
LIST OF FIGURES .......................................................................................................... vii
INTRODUCTION ...............................................................................................................1

Anchoring Effects in Numeric Estimation .......................................................2
Relationship between Anchoring Effects and Knowledge Level .....................6
Previous Theoretical Arguments Regarding Knowledge and
Anchoring Effects ......................................................................................6
Previous Empirical Findings Regarding Knowledge and Anchoring
Effects ........................................................................................................7
A Framework for Quantitative Estimation .....................................................10
Why Considering Type of Knowledge is Important for Anchoring
Research ..........................................................................................................12
Overview of Current Studies ..........................................................................14
CHAPTER 1 FULL VS. NO KNOWLEDGE ...................................................................17

Method ............................................................................................................18
Participants and Design ...........................................................................18
Materials ..................................................................................................19
Procedures ...............................................................................................19
Results.............................................................................................................21
Subjective Knowledge Judgments ...........................................................21
Accuracy of Estimates .............................................................................21
Anchoring Effects ....................................................................................25
Measures of Accuracy and Anchoring Effects ........................................27
Subjective Knowledge Judgments and Anchoring Effects .....................28
Additional Analyses ................................................................................29
Discussion .......................................................................................................30
Relationship between Accuracy, Error, and Bias ....................................32
CHAPTER 2 RELEVANT VS. IRRELEVANT KNOWLEDGE ....................................35

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Method ............................................................................................................36
Participants and Design ...........................................................................36
Procedure .................................................................................................37
Results.............................................................................................................38
Anchoring Effects ....................................................................................38
Discussion .......................................................................................................39
CHAPTER 3 DIFFERENT TYPES OF KNOWLEDGE ..................................................42

Method ............................................................................................................43
Participants and Design ...........................................................................43
Materials and Procedures ........................................................................43
Results.............................................................................................................45
Subjective Knowledge Judgments ...........................................................45
Accuracy of Estimates .............................................................................47
iv
Anchoring Effects ....................................................................................50
Measures of Accuracy and Anchoring Effects ........................................53
Subjective Knowledge Measures and Anchoring Effects .......................55
Discussion .......................................................................................................56
CHAPTER 4 MEASURING DIFFERENT TYPES OF KNOWLEDGE .........................59

Method ............................................................................................................61
Participants ..............................................................................................61
Materials ..................................................................................................62
Procedure .................................................................................................62
Results.............................................................................................................63
Measures of Knowledge ..........................................................................63
Relationship Between Measures of Knowledge ......................................66
Relationship between Knowledge Measures and Accuracy of
Anchored Estimates .................................................................................68
Anchoring effects and Knowledge Measures ..........................................69
Accuracy of Anchored Estimates and Anchoring Effects .......................71
Exploratory Analyses ..............................................................................72
Discussion .......................................................................................................79
Final Points ..............................................................................................83
CHAPTER 5 SUMMARY, IMPLICATIONS, AND FUTURE RESEARCH .................84

The Importance of Considering Knowledge Level ........................................86
Knowledge, Confidence, and Anchoring Effects ...........................................92
Knowledge and Different Types of Anchoring ..............................................93
Knowledge Level and Other Biases ...............................................................94
Theoretical Implications .................................................................................95
Practical Implications for Debiasing Anchoring Effects ................................98
Final Thoughts ................................................................................................99
APPENDIX A LISTS OF AFRICAN COUNTRIES USED IN STUDY 1 ....................100
APPENDIX B INSTRUCTIONS USED IN STUDY 2 ..................................................101
APPENDIX C STIMULI PRESENTED IN STUDY 2 ...................................................102
APPENDIX D LIST OF AFRICAN COUNTRIES USED IN STUDY 3 ......................103
5

APPENDIX E LISTS OF STATES USED IN STUDY 4 ...............................................104
REFERENCES ................................................................................................................105
v