Preface p. v
p. 2
An Introductory Overview p. 3
Ways of Knowing p. 4
Intuition and Reasoning Versus Empirical Observation: An Example p. 7
The Scientific Method p. 10
Characteristics of Scientific Observations p. 11
Rival Explanations p. 14
Defining the Terms p. 14
Replication p. 15
Internal and External Validity p. 15
Conducting a Research Study p. 16
Exercises p. 19
p. 22
Ethics in Research p. 23
Guidelines for Psychologists p. 24
The Basic Ethical Dilemma p. 25
The Six General Ethical Principles p. 27
Specific Ethical Issues in Research with Humans p. 28
Risk or Freedom From Harm p. 28
Informed Consent p. 29
Debriefing p. 32
Privacy p. 32
Ethical Treatment of Animals as Research Subjects p. 33
Special Issues About the Ethics of Research p. 34
Who Decides What Is "Right?" p. 34
Ethics of Funding p. 34
Ethics and Statistics p. 35
What Becomes of What You Find? p. 36
A Final Note for New Researchers p. 38
Exercises p. 38
p. 40
Variables p. 41
Variables Versus Constants: Definitions and Examples p. 42
How to Identify Variables Versus Constants p. 44
Types of Variables p. 45
Types of Relationships p. 47
No Relationship p. 47
Correlation p. 47
Causality p. 49
Necessary, Sufficient, and Contributory Causes p. 50
Simple Versus Multiple Causation p. 51
Exercises p. 53
p. 56
Measuring Variables p. 57
Data-Gathering Techniques p. 58
Behavioral Observations p. 58
Self-Reports p. 58
Behavioral Ratings p. 60
Archival Records p. 60
Physical Trace Approach p. 61
Measurement p. 62
Operational Definitions: Measuring Variables p. 63
Operational Definitions: Establishing Research Conditions p. 64
Reliability and Validity p. 66
Reliability p. 66
Validity p. 69
Levels (or Scales) of Measurement p. 72
Sensitivity of Measurements p. 75
Exercises p. 75
p. 78
Descriptive Statistics p. 79
Populations and Samples p. 80
About the Computations in This Text p. 80
Frequency p. 81
Graphing Frequencies p. 82
Grouped Frequencies p. 84
Probability p. 86
Central Tendency p. 89
Mode p. 89
Median p. 89
Mean p. 93
Means Versus Medians: The Case of Outliers p. 94
Distributions of Scores p. 95
The Normal Distribution p. 96
Skewed Distributions p. 97
Variability p. 98
Variance and Standard Deviation p. 98
Median Absolute Deviation p. 101
Standard Deviations Versus the Median Absolute Deviation: The Case of Outliers p. 104
Range p. 105
Number of Categories/Values p. 105
The Variation Ratio p. 106
Selecting Appropriate Descriptive Statistics p. 106
Simple Data Transformations p. 106
z-Scores p. 112
z-Scores as Inferential Statistics: Areas Under the Normal Curve p. 114
Exercises p. 120
p. 124
Hypothesis Testing p. 125
Representativeness and Sampling Procedures p. 127
Random Sampling p. 127
Stratified Random Sampling p. 129
Available Samples and Convenience Sampling p. 129
Statistical Hypotheses p. 130
The Null Hypotheses (H[subscript 0]) p. 130
Research or Alternate Hypothesis (H[subscript 1]) p. 131
Sampling Distributions p. 133
The Shape of the Sampling Distribution p. 136
The Average of the Sampling Distribution p. 138
Variability of Sampling Distributions p. 138
Probabilities of Samples p. 139
Making the Decision p. 140
Significance Levels ([alpha]) p. 142
Critical Values p. 143
Tables of Critical Values p. 144
Have We Made the Correct Decision? p. 145
Threats to the Validity of Hypothesis-Testing: Pitfalls to Avoid p. 149
Statistical Versus Practical and Psychological Significance p. 149
The Relevant Error Rate and "Accepting" The Null Hypothesis p. 150
The Arbitrary Cut-off Point Between "Rare" and "Common" Events p. 151
Proposed Alternatives to the Null-Hypothesis-Testing Procedure p. 152
A Call for Compromise: Using a Combination of Approaches p. 153
Exercises p. 154
p. 156
General Research Methods p. 157
The Experimental Method p. 158
The Logic of Experiments p. 160
An Overview of the Experimental Method p. 166
An Alternative to Random Assignment: Repeated Measures p. 169
Research Settings for Experiments: Laboratory Versus Field Experiments p. 169
Quasi-Experimental Research Methods p. 171
Non-Equivalent Groups Designs p. 171
Time-Series Designs p. 173
Two Approaches to Analyzing the Results p. 174
Summary of Quasi-Experimental Methods p. 175
Correlational Methods p. 175
Naturalistic Observation p. 178
Summary of the Correlational Method p. 180
Exercises p. 181
p. 184
Correlation Coefficients p. 185
Magnitude p. 186
Direction p. 188
Graphing the Relationship Between Two Variables p. 189
Selecting the Appropriate Correlation Coefficient p. 191
Pearson Product-Moment Correlation Coefficient p. 193
The Pearson r as an Inferential Statistic: Testing the Null Hypothesis p. 196
Spearman Rank-Order Correlation Coefficient p. 197
The Spearman r as an Inferential Statistic: Testing the Null Hypothesis p. 199
Tied Ranking Procedure p. 200
Correlating Nominal Data p. 202
Phi Coefficient p. 203
Testing the Difference Between Two Correlations p. 206
Exercises p. 208
p. 212
Introduction to Regression Analysis p. 213
The Logic Behind Simple Regression Analysis p. 214
The Regression Equation p. 217
About the Regression Equation p. 219
Assumptions and Limitations of the Least-Squares Method of Regression p. 221
Linearity p. 222
Normal Distributions and Homoscedasticity p. 224
Evaluating Y': How Accurate Are Our Predictions? p. 227
A Short-Cut for Computing the Standard Error of the Estimate p. 235
z-Scores and Regression Analysis p. 236
Coefficient of Determination p. 238
Using Venn Diagrams to Illustrate r[superscript 2] p. 241
The Basic Concepts of Multiple Regression p. 242
Using Venn Diagrams to Illustrate Multiple Regression and R[superscript 2] p. 243
Multicollinearity p. 246
Exercises p. 248
p. 252
Designing Experiments and Quasi-Experiments p. 253
One-way Designs p. 255
Factorial Designs and the Concept of Interaction: "It Depends" p. 256
Multiple Determinants (or Predictors) of Behavior p. 257
Contingencies Among Determinants: The Essence of Interaction p. 258
Terminology and Notation Systems for Factorial Designs p. 261
Factorial Designs and Confounds p. 263
The Research Questions Addressed in Factorial Designs p. 264
Selecting Only the Necessary Independent Variables p. 267
Selecting the Necessary Levels of the Independent Variables p. 268
No-Treatment Control Group p. 271
Placebo Control Groups p. 272
Research Designs p. 273
Comparisons Between Groups Versus Repeated Measures p. 273
Testing Participants Repeatedly in Within-Subjects Designs p. 273
Advantages of Within-Subjects Designs p. 275
Disadvantages of Within-Subjects Designs p. 277
Counterbalancing p. 279
Summary of Within-Subjects Designs p. 285
Advantages and Disadvantages of Between-Subjects Designs p. 285
Matching Designs p. 286
Some General Confounds: Threats to Internal Validity p. 287
Maturation p. 287
History p. 288
Regression Toward the Mean p. 288
Instrumentation p. 289
Mortality p. 290
Sensitization p. 290
Pretest-Posttest Designs: The Need for a Control Group p. 291
Selecting Within-Subjects Factors for Mixed Designs p. 294
The Special Case of Age as an Independent Variable p. 297
Steps in Designing an Experiment or Quasi-Experiment p. 298
Exercises p. 300
p. 306
The z-Test and t-Test: Analyzing Data from One-and Two-Group Designs p. 307
The z-Test: When the Population Standard Deviation ([sigma]) Is Known p. 308
z-Test: Application 1: When the Population Mean ([mu]) Is Known p. 308
z-Test Application 2: When the Population Mean ([mu]) Is Being Tested p. 317
Requirements for the z-Test p. 318
The t-Test: When the Population Standard Deviation ([sigma]) Is Unknown p. 320
One-Sample t-Test p. 322
Two-Sample t-Test: Independent Samples From a Between-Subjects Design p. 326
Two-Sample t-Test: Related Samples From a Within-Subjects or Matching Design p. 333
The Limited Applicability of z- and t-Tests p. 338
Exercises p. 339
p. 342
Analysis of Variance p. 343
Sources of Variation p. 345
Between-Subjects Designs p. 345
Within-Subjects Designs p. 346
Factorial Designs p. 347
Mixed Designs p. 347
Computing Sums of Squares p. 349
One-way BS-ANOVA p. 349
Two-way BS-ANOVA p. 353
One-way RM-ANOVA p. 356
Degrees of Freedom p. 359
Mean Squares p. 364
The F-Ratio p. 365
Testing the Significance of F p. 366
Post Hoc Analyses p. 367
Dunn's Multiple Comparisons Procedure p. 368
Example of a One-way BS-ANOVA p. 373
Example of a 2 [times] 3 (Two-way) BS-ANOVA p. 379
Example of a One-way RM-ANOVA p. 391
Exercises p. 399
p. 406
Nonparametric Tests for Experiments and Quasi-Experiments p. 407
Nominal Scales p. 410
Between-Subjects Designs: Chi-Square (X[superscript 2]) p. 410
Within-Subjects Designs: Cochran's Q p. 416
Ordinal Scales p. 422
Between-Subjects Designs: The Wilcoxon Rank Sum Test and the Kruskal-Wallis H p. 422
Within-Subjects Designs: Wilcoxon Signed Ranks Test (a.k.a. the Wilcoxon W) p. 428
A Cautionary Note about When to Select the Appropriate Statistic p. 431
Exercises p. 432
p. 438
Estimation and Confidence Intervals p. 439
Confidence Intervals for the Mean p. 441
Finding the Margin of Error: The Maximum Error of the Estimate p. 441
Confidence Interval: The Range of Likely Values of the Population Mean p. 445
Summary: Steps in Computing the Confidence Interval for the Mean p. 447
Confidence Intervals for Proportions (or Percentages) p. 447
Numerical Examples of Confidence Intervals for Proportions (or Percentages) p. 448
Limitations of Confidence Intervals for Proportions (or Percentages) p. 450
Confidence Intervals for Pearson Correlations p. 451
Numerical Example of Confidence Intervals for the Pearson Correlation p. 453
Minimum Differences Between Treatment Means p. 455
Minimum Differences in Two-Group Between-Subjects Designs p. 456
Minimum Differences in Two-Treatment Related-Samples Designs p. 460
Confidence Intervals Versus Significance Testing p. 464
Numerical Example of Confidence Intervals That Do Not Overlap p. 466
Numerical Example of Confidence Intervals That Overlap p. 467
Confidence Intervals and Statistical Power p. 471
Renewing the Call for Compromise: Combining the Approaches p. 475
Exercises p. 475
p. 478
Single-Subject Research Design p. 479
Key Elements of Single-Subject Research p. 480
Elements of Measurement p. 481
Design Phases in Single-Subject Research Designs p. 486
Presentation of Data p. 486
Threats to the Validity of Data from Single-Subject Designs p. 488
Specific Research Designs p. 490
ABAB Designs p. 490
Multiple-Baseline Designs p. 493
The Changing Criterion Design p. 498
Alternating Treatment Designs p. 501
Mixed Designs p. 504
Single-Subject Designs for Applied and Basic Research Questions p. 506
Evaluation of Data from Single-Subject Designs p. 507
Visual Inspection p. 508
Interpreting the Data from Single-Subject Research p. 514
Potential Confounds and Problems in the Visual Interpretation of Data p. 516
Resources for Further Study p. 518
Exercises p. 519
p. 524
Qualitative Research Methods and Analysis p. 525
Qualitative Methods for Gathering Data p. 526
Observation p. 527
Interviews p. 532
Textual Analysis p. 539
Transcription p. 540
Reliability and Validity in Qualitative Research p. 542
Triangulation of Methods: Increasing the Validity p. 543
A Case Study Illustrating Triangulation of Qualitative Research Methods p. 544
Statistics for Qualitative Methods p. 546
The Future of Qualitative Methods p. 548
Suggestions for Further Reading p. 548
Exercises p. 549
Appendix A p. 0
Ethical Principles of Psychologists and Code of Conduct p. 1
Introduction p. 3
Preamble p. 5
General Principles p. 5
Competence p. 5
Integrity p. 6
Professional and Scientific Responsibility p. 6
Respect for People's Rights and Dignity p. 6
Concern for Others' Welfare p. 6
Social Responsibility p. 7
Ethical Standards p. 7
General Standards p. 7
Evaluation, Assessment, or Intervention p. 13
Advertising and Other Public Statements p. 15
Therapy p. 16
Privacy and Confidentiality p. 19
Teaching, Training Supervision, Research, and Publishing p. 21
Forensic Activities p. 26
Resolving Ethical Issues p. 28
Appendix B p. 0
Statistical Tables p. 1
Appendix C p. 0
Introduction to Statistical Power p. 1
Two Variances p. 1
Using the Two Variances to Test the Null Hypothesis p. 3
Statistical Power p. 5
Maximizing the Power in a Study p. 7
Adequate Sample Size p. 7
Lower Significance ([alpha]) Levels p. 9
Selecting Designs with More Inherent Power p. 9
Power Analysis p. 14
Exercises p. 20
Appendix D p. 0
Reporting the Research p. 1
Methods of Dissemination p. 1
Presentations at Professional Meetings p. 1
Written Reports p. 4
Electronic Dissemination p. 5
General Writing Style p. 6
Some Specific Issues and Common Errors p. 8
Re-writing p. 9
Plagiarism p. 10
APA Format and Manuscript Preparation p. 11
Sections of an APA-Format Research Report p. 12
Examples of References Using the APA Format p. 19
Manuscript Headings p. 23
Sample Manuscripts p. 24
Appendix E p. 0
Answers for the Odd-Numbered Exercises p. 1
Appendix F p. 0
References p. 1
Glossary p. 1
Index p. 1