Tài liệu Marketing Research Methods in SAS - Experimental Design, Choice, Conjoint, and Graphical Techniques - Pdf 10

Marketing Research
Methods in SAS
Experimental Design, Choice,
Conjoint, and Graphical Techniques
Warren F. Kuhfeld
October 1, 2010
SAS 9.2 Edition
MR-2010
Copyright
c
 2010 by SAS Institute Inc., Cary, NC, USA
This information is provided by SAS as a service to its users. The te xt, macros, and code are provided
“as is.” There are no warranties, expressed or implied, as to merchantability or fitness for a particular
purpose regarding the accuracy of the materials or code contained herein.
SAS
r

, SAS/AF
r

, SAS/ETS
r

, SAS/GRAPH
r

, SAS/IML
r

, SAS/QC
r

chapter in the book, and it contains numerous examples covering a wide range of choice experiments
and choice designs. Study the chapter Experimental Design: Effici ency, Coding, and Choice
Designs before tackling this chapter.
Multinomial Logit Mo del s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665–680
This SUGI paper discusses the multinomial logit model. A travel example is discussed.
Conjoint Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 681–801
This chapter discusses conjoint analysis. Examples range from simple to complicated. Topics include
design, data collection, analysis, and simulation. PROC TRANSREG documentation that describes
just those options that are most likely to be used in a conjoint analysis is included.
The Macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 803–1211
This chapter provides e xamples and documentation for all of the autocall macros used in this book.
Linear Models and Conjoint Analysis with Nonlinear Spline Transformations 1213–1230
This chapter is based on an AMA ART (American Marketing Association Advanced Research Tech-
niques) Forum paper and discusses splines, which are nonlinear functions that can be useful in regression
and conjoint analysis.
Graphical Scatter Plots of Labeled Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1231–1261
This chapter is based on a paper that appeared in the SAS journal Observations that discusses a macro
for graphical scatter plots of labeled points. ODS Graphics is also mentioned.
Graphical Methods for Marketing Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1263–1274
This chapter is based on a National Computer Graphics Association Conference presentation and
discusses the mathematics of biplots, correspondence analysis, PREFMAP, and MDPREF.

Contents
Preface 19
About this Edition 21
Getting Help and Contacting Technical Support 25
Marketing Research: Uncovering Competitive Advantages 27
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Perceptual Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Coding and the Efficiency of a Choice Design . . . . . . . . . . . . . . . . . . . . . . . . 81
Orthogonal Coding and the ZERO=’ ’ Option . . . . . . . . . . . . . . . . . . . . . . . . 89
Orthogonally Coding Price and Other Quantitative Attributes . . . . . . . . . . . . . . 91
The Number of Factor Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Randomization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Random Number Seeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Duplicates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Orthogonal Arrays and Difference Schemes . . . . . . . . . . . . . . . . . . . . . . . . . 95
Canonical Correlations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Optimal Generic Choice Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Block Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
The Process of Designing a Choice Experiment . . . . . . . . . . . . . . . . . . . . . . . 123
Overview of the Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Example 1: Orthogonal and Balanced Factors, the Linear Arrangement Approach . . . . 127
Example 2: The Linear Arrangement Approach with Restrictions . . . . . . . . . . . . . 156
Example 3, Searching a Candidate Set of Alternatives . . . . . . . . . . . . . . . . . . . 166
CONTENTS 7
Example 4, Searching a Candidate Set of Alternatives with Restrictions . . . . . . . . . 177
Example 5, Searching a Candidate Set of Choice Sets . . . . . . . . . . . . . . . . . . . . 188
Example 6, A Generic Choice Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Example 7, A Partial-Profile Choice Experiment . . . . . . . . . . . . . . . . . . . . . . 207
Example 8, A MaxDiff Choice Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
Choice Design Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Efficient Experimental Design with Marketing Research Applications 243
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Design of Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Design Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

From the Linear Arrangement to a Choice Design . . . . . . . . . . . . . . . . . . . . . . 311
Testing the Design Before Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Evaluating the Design R elative to the Optimal Design . . . . . . . . . . . . . . . . . . . 319
Generating the Questionnaire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Entering the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Processing the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Binary Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Fitting the Multinomial Logit Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Multinomial Logit Model Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Probability of Choice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Custom Questionnaires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Processing the Data for Custom Questionnaires . . . . . . . . . . . . . . . . . . . . . . . 337
Vacation Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
Set Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Designing the Choice Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
The %MktEx Macro Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
Examining the Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
From a Linear Arrangement to a Choice Design . . . . . . . . . . . . . . . . . . . . . . . 356
Testing the Design Before Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . 360
CONTENTS 9
Generating the Questionnaire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369
Entering and Processing the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
Binary Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372
Quantitative Price Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377
Quadratic Price Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380
Effects Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382
Alternative-Specific Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
Vacation Example and A rtifici al Data Generation . . . . . . . . . . . . . . . . . . . . 393
Vacation Example with Alternative-Speci fic Attributes . . . . . . . . . . . . . . . . . 410
Choosing the Numb e r of Choice Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411

Generating Artificial Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520
Processing the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521
Cross-Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523
Multinomial Logit Model Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524
Modeling Subject Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529
Allocation of Prescription Drugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535
Designing the Allocation Expe riment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535
Processing the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543
Coding and Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 550
Multinomial Logit Model Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 550
Analyzing Proportions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 552
Chair Design with Generic Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556
Generic Attributes, Alternative Swapping, Large Candidate Set . . . . . . . . . . . . . . 557
Generic Attributes, Alternative Swapping, Small Candidate Set . . . . . . . . . . . . . . 564
Generic Attributes, a Constant Alternative, and Alternative Swapping . . . . . . . . . . 570
Generic Attributes, a Constant Alternative, and Choice Set Swapping . . . . . . . . . . 574
Design Algorithm Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 579
Initial Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580
Improving an Existing Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580
When Some Choice Sets are Fixed in Advance . . . . . . . . . . . . . . . . . . . . . . . 583
Partial Profiles and Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595
Pairwise Partial-Profile Choice Des ign . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595
Linear Partial-Profile Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 602
Choice from Triples; Partial Profiles Constructed Using Res trictions . . . . . . . . . . . 604
Six Alternatives; Partial Profiles Constructed Using Restrictions . . . . . . . . . . . . . 610
CONTENTS 11
Five-Level Factors; Partial Profiles Constructed Using Restrictions . . . . . . . . . . . . 626
Partial Profiles from Block Designs and Orthogonal Arrays . . . . . . . . . . . . . . 640
Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663
Multinomial Logit Mode ls 665

Metric Conjoint Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 722
Analyzing Holdouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 737
Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 739
Summarizing Results Across Subjects . . . . . . . . . . . . . . . . . . . . . . . . . . . . 743
Spaghetti Sauce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 751
Create an Efficient Experimental Design with the %MktEx Macro . . . . . . . . . . . . 751
Generating the Questionnaire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 760
Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 764
Metric Conjoint Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 765
Simulating Market Share . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 769
Simulating Market Share, Maximum Utility Model . . . . . . . . . . . . . . . . . . . . . 772
Simulating Market Share, Bradley-Terry-Luce and Logit Models . . . . . . . . . . . . . 778
Change in Market Share . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 780
PROC TRANSREG Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789
PROC TRANSREG Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 789
Algorithm Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 790
Output Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791
Transformations and Expansions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 792
Transformation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 794
BY Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 795
ID Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 796
WEIGHT Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 796
Monotone, Spline, and Monotone Spline Comparisons . . . . . . . . . . . . . . . . . . . 796
Samples of PROC TRANSREG Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 799
Metric Conjoint Analysis with Rating-Scale Data . . . . . . . . . . . . . . . . . . . . . . 799
Nonmetric Conjoint Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 799
Monotone Splines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800
Constraints on the Utilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800
A Discontinuous Price Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 801
CONTENTS 13

%MktBSize Macro Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 994
%MktDes Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 995
14 CONTENTS
PROC FACTEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 995
%MktDes Macro Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 997
%MktDes Macro Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1003
%MktDups Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1004
%MktDups Macro Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1009
%MktDups Macro Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1011
%MktEval Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1012
%MktEval Macro Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1014
%MktEval Macro Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1016
%MktEx Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1017
Orthogonal Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1018
Randomization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1026
Latin Squares and Graeco-Latin Square Designs . . . . . . . . . . . . . . . . . . . . . . . 1026
Split-Plot Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1031
Candidate Set Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1045
Coordinate Exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1045
Aliasing Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1047
%MktEx Macro Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1051
%MktEx Macro Iteration History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1053
%MktEx Macro Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1055
Advanced Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1079
%MktKey Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1090
%MktKey Macro Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1091
%MktLab Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1093
%MktLab Macro Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1101
%MktLab Macro Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1104
%MktMDiff Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1105

Background and History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1214
The General Linear Univariate Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1214
Polynomial Splines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1215
Splines with Knots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1216
Derivatives of a Polynomial Spline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1218
Discontinuous Spline Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1219
Monotone Splines and B-Splines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1221
16 CONTENTS
Transformation Regression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1222
Degrees of Freedom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1223
Dependent Variable Transformations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1223
Scales of Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1224
Conjoint Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1224
Curve Fitting Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1225
Spline Functions of Price . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1227
Benefits of Splines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1227
Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1230
Graphical Scatter Plots of Labeled Points 1231
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1231
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1231
An Overview of the %PlotIt Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1232
Changes and Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1233
Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1233
Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1245
Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1246
Appendix: ODS Graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1247
Graphical Methods for Marketing Research 1263
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1263
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1263
Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1264

people. I would like to thank Joel Huber, Ying So, Randy Tobias, and John Wurst. My involvement
in the area of experimental design and choice modeling can be traced to several conversations with
Mark Garratt in the early 1990’s and then to the influence of Don Anderson, Joel Huber, Jordan
Louviere, and Randy Tobias. I first learned about choice modeling at a tutorial taught by Jordan
Louviere at the ART Forum. Later, as I got into this area, Jordan was very helpful at key times in
my professional development. Don Anderson has been a great friend and influence over the years. Don
did so much of the pioneering work on choice designs. There is no doubt that his name should be
referenced in this book way more than it is. Joel Huber got me started on the work that became the
%ChoicEff macro. Randy Tobias has been a great colleague and a huge help to me over the years in
all areas of experimental design, and many components of the %MktEx macro and other design macros
are based on his ideas and his work. Randy wrote PROC OPTEX and PROC FACTEX which provide
the foundation for my design work. My work on balanced incomplete block designs can be traced to
conversations with John Wurst.
Don Anderson, Warwick de Launey, Nam-Ky Nguyen, Shanqi Pang, Neil Sloane, Chung-yi Suen, Randy
Tobias, J.C. Wang, and Yingshan Zhang kindly helped me with some of the orthogonal arrays in the
%MktEx macro. Brad Jones advised me on coordinate exchange. Much of our current success with
creating highly restricted designs is due to the difficult and very interesting design problems brought
to me by Johnny Kwan. I have also learned a great deal from the interesting and challenging problems
brought to me by Ziad Elmously.
19
There are a few other people that I would like to acknowledge. Without these people, I would have never
been in the position to write a book such as this. From my undergraduate days at Kent State, I would
like to thank Roy Lilly

, Larry Melamed, Steve Simnick and especially my adviser Ben Newberry.
From graduate school at UNC, I would like to thank Ron Helms, Keith Muller, and especially my
adviser Forrest Young

. From SAS, I would like to thank Bob Rodriguez, Warren Sarle, and all of my
colleagues in SAS/STAT Research and Development. It is great to work with such a smart, talented,


It is sad that so many people that I acknowledge have passed away since I started working on this book. I wish I
could thank all of these people for their role in helping me to get to where I am today.
20
About this Edition
The 2010 edition of Marketing Research Methods in SAS is a partial revision of the 2009 book. I
did not have time to rewrite everything that I would have liked to rewrite. I do many different things
professionally, way more than most readers of this book know. Those other things take most of my
time, and it is hard to find the large block of time that I need to completely modify a piece of work this
size every time there is an enhancement or innovation in the design macros. In this edition, I added
new material and also added some guidance in the ensuing paragraphs about how to navigate through
this book.
This edition has explicit instructions about how to contact Technical Support when you have questions
or problems. See page 25 for more information. While I have never minded getting your questions,
they really need to go to Technical Support first. I am not always in the office. Sometimes I am out
backpacking without any contact with the outside world. Contacting Technical Supp ort will ensure
that your question is seen and addressed in a timely manner.
This edition contains some major new features that were not in the 2005 edition and one major new
feature that was not in the 2009 edition. With this 2010 edition, the %ChoicEff macro now allows
you to specify a restrictions macro. You can use it to specify within alternative restrictions, within
choice se t (and across alternative) restrictions, and even restrictions across choice sets. You can specify
restrictions directly with the alternative-swapping algorithm. You no longer need to make a choice
design with the %MktEx macro or with the choice-set-swapping algorithm in the %ChoicEff macro
when there are restrictions.
Most of this book is about experimental design. In particular, most of it is about designing choice
experiments. This is a big topic with multiple tools and multiple approaches with multiple nuances, so
hundreds of pages are devoted to it. This can be intimidating when you are first getting started. The
following information can help you get started:
• If you are new to choice modeling and choice design, and you want to understand what you are
doing, you should start by reading the “Experimental Design: Efficiency, Coding, and Choice

“factorial design” interchangeably to refer to designs that will be used for a linear model such as a
conjoint analysis. I no longer refer to a design constructed by the %MktEx macro that is converted to a
choice design by the %MktRoll macro as a “linear design.” Instead, I use the term “linear arrangement”
as a short-hand for “linear arrangement of a choice design” to refer to a design that will ultimately
be used for a choice design, but is currently arranged with one row per choice set and one column for
every attribute of every alternative. The linear arrangement of a choice design can be constructed and
evaluated by pretending that it will be used for a linear model with one factor for every attribute of
every alternative. This is one way in which you can make a choice design, and it is discusse d in detail
in this book.
If you had to pick one approach to solve all of your design problems, and you did not have time to
learn about all of the other ways you could go about designing a choice experiment, here is what
I would recommend. Use the %MktEx macro to make a candidate set of alternatives, and use the
%ChoicEff macro to create a choice design from it. If there are any restrictions on your design, use the
restrictions= option in the %ChoicEff macro to impose the restrictions. The restrictions= option
in the %ChoicEff macro is new with this edition of the book and macros. Restrictions can be within
alternative, within choice set (and across alternative), or eve n across choice sets. You can impose
restrictions to prevent certain combinations of alternatives from occurring together, to minimize the
burden on the subjects, to eliminate dominated alternatives, to make the design more realistic, or for
any other reason. I have not eliminated the hundreds of pages of this book that are devoted to other
ways to make choice designs, because those pages contain a lot of useful information. Rather, I simply
point out that you can selectively devote your attention to different parts of the b ook and concentrate
on using the %ChoicEff macro with a candidate set of alternatives for most of your choice design needs.
Each of the last few editions has relied much more heavily on the %ChoicEff macro than preceding
editions did. The %ChoicEff macro is heavily used both for design construction and for design evalua-
tion. You should always use it to evaluate designs before data are collected. This has always been good
advice, but with the addition of the standardized orthogonal contrast coding in PROC TRANSREG
(which the macro calls) plus some new options and output, the %ChoicEff macro now provides a clearer
picture of choice design goodness for many choice designs. In particular, it provides a measure of design
efficiency on a 0 to 100 scale for at least some choice designs. See page 81 for more information.
22

who make judgments based on the actual design. If I had real data in an example, I would no longer be
able to change and enhance the design strategy for that example. Many of the examples have changed
many times over the years as better design software and strategies became available. In this edition,
like all previous editions, the emphasis is on showing design strategies not on illustrating the analysis
of the data.
The orthogonal array catalog is essentially complete up through 143 runs,

with pretty good coverage
from 144 to 513 runs, and spotty coverage beyond 513 runs. New arrays are being discovered regularly.
If you know of any orthogonal arrays that are not in my catalog, please e-mail Warren.Kuhfeld at
sas.com. I would particularly like to hear from you if you know how to make any of the arrays that
are missing. Also, if you know how to construct any of these difference schemes, I would appreciate
hearing from you: D(60, 36, 3); D(102, 51, 3); D(60, 21, 4); D(112, 64, 4); D(30, 15, 5); D(35, 17, 5);
D(40, 25, 5); D(55, 17, 5); D(60, 25, 5); D(65, 25, 5); D(85, 35, 5); D(60, 11, 6); D(84, 16, 6); D(35,
11, 7); D(63, 28, 7); D(40, 8, 10); and D(30, 7, 15). The notation D(r, c, s) refers to an r ×c matrix of
order s. You can always go to http://support.sas.com/techsup/technote/ts723.html to see the
current state of the orthogonal array catalog.

There are a few missing designs in 108 runs. I would welcome help in making them.
23
ODS Graphics is used throughout the book. With ODS Graphics and SAS 9.2, statistical procedures
produce graphs as automatically as they produce tables, and graphs are now integrated with tables in
the ODS output. See 1247 for the sec tion of the book that says the most about ODS Graphics. Also
see “Chapter 21, Statistical Graphics Using ODS” in SAS/STAT documentation for more on ODS
Graphics: http://support.sas.com/documentation/. You can learn more about ODS Graphics
in my new book, Stati stical Graphics in SAS: An Introduction to the Graph Template
Language and the Statistical Graphics Procedures. You can learn more about the book at
http://support.sas.com/publishing/authors/kuhfeld.html.
I hope you like this edition. Fe edback is welcome. Your feedback can help make these tools be tter.
24

Help → About SAS.
Please include information about the version of the macros that you have installed and are using. You
can find this information by submitting the following statement before running any of the macros:
%let mktopts = version;.
25


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