Preface 

xv  

Drawing Statistical Conclusions 


1  (26) 


2  (3) 

Statistical Inference and Study Design 


5  (5) 

Measuring Uncertainty in Randomized Experiments 


10  (4) 

Measuring Uncertainty in Observational Studies 


14  (1) 


15  (6) 


21  (1) 


22  (5) 

Inference Using tDistributions 


27  (26) 


28  (2) 

OneSample tTools and the Paired tTest 


30  (5) 

A tRatio for Twosample Inference 


35  (7) 

Inferences in a Twotreatment Randomized Experiment 


42  (2) 


44  (3) 


47  (1) 


48  (5) 

A Closer Look at Assumptions 


53  (28) 


54  (3) 

Robustness of the Twosample tTools 


57  (4) 

Resistance of the Twosample tTools 


61  (1) 

Practical Strategies for the Twosample Problem 


62  (3) 

Transformations of the Data 


65  (5) 


70  (1) 


71  (1) 


72  (9) 

Alternatives to the tTools 


81  (27) 


82  (3) 


85  (6) 

Other Alternatives for Two Independent Samples 


91  (4) 

Alternatives for Paired Data 


95  (3) 


98  (3) 


101  (1) 


101  (7) 

Comparisons Among Several Samples 


108  (34) 


109  (4) 

Comparing Any Two of the Several Means 


113  (3) 

The Oneway Analysis of Variance FTest 


116  (8) 

Robustness and Model Checking 


124  (2) 


126  (7) 


133  (1) 


134  (8) 

Linear Combinations and Multiple Comparisons of Means 


142  (25) 


143  (3) 

Inferences About Linear Combinations of Group Means 


146  (7) 


153  (1) 

Some Multiple Comparison Procedures 


154  (4) 


158  (3) 


161  (1) 


162  (5) 

Simple Linear Regression: A Model for the Mean 


167  (31) 


168  (3) 

The Simple Linear Regression Model 


171  (4) 

Least Squares Regression Estimation 


175  (5) 


180  (7) 


187  (3) 


190  (1) 


191  (7) 

A Closer Look at Assumptions for Simple Linear Regression 


198  (27) 


199  (3) 

Robustness of Least Squares Inferences 


202  (2) 

Graphical Tools for Model Assessment 


204  (3) 

Interpretation After Log Transformations 


207  (2) 

Assessment of Fit Using the Analysis of Variance 


209  (4) 


213  (4) 


217  (1) 


218  (7) 


225  (30) 


226  (4) 


230  (4) 

Specially Constructed Explanatory Variables 


234  (7) 

A Strategy for Data Analysis 


241  (1) 

Graphical Methods for Data Exploration and Presentation 


242  (4) 


246  (1) 


247  (1) 


248  (7) 

Inferential Tools for Multiple Regression 


255  (36) 


256  (3) 

Inferences About Regression Coefficients 


259  (9) 

ExtraSumsofSquares FTests 


268  (7) 


275  (6) 


281  (1) 


281  (10) 

Model Checking and Refinement 


291  (34) 


292  (5) 


297  (3) 

A Strategy for Dealing with Influential Observations 


300  (2) 

CaseInfluence Statistics 


302  (6) 


308  (6) 


314  (2) 


316  (1) 


317  (8) 

Strategies for Variable Selection 


325  (37) 


326  (6) 

Specific Issues Relating to Many Explanatory Variables 


332  (5) 

Sequential Variable Selection Techniques 


337  (4) 

Model Selection Among All Subsets 


341  (4) 

Analysis of the Sex Discrimination Data 


345  (4) 


349  (5) 


354  (1) 


355  (7) 

The Analysis of Variance for Twoway Classifications 


362  (35) 


363  (4) 

Additive and Nonadditive Models for Twoway Tables 


367  (4) 

Analysis of the Seaweed Grazer Data 


371  (9) 

Analysis of the Pygmalion Data 


380  (7) 


387  (4) 


391  (1) 


392  (5) 

Multifactor Studies Without Replication 


397  (27) 


398  (4) 

Strategies for Analyzing Tables with One Observation per Cell 


402  (1) 

Analysis of the Chimpanzee Learning Times Study 


403  (6) 

Analysis of the Soybean Data 


409  (6) 


415  (4) 


419  (1) 


420  (4) 

Adjustment for Serial Correlation 


424  (26) 


425  (2) 

Comparing the Means of Two Time Series 


427  (6) 

Regression After Transformation in the AR(1) Model 


433  (3) 

Determining if Serial Correlation is Present 


436  (3) 

Diagnostic Procedures for Judging the Adequacy of the AR(1) Model 


439  (4) 


443  (1) 


443  (1) 


444  (6) 


450  (33) 


451  (3) 

Tools and Strategies for Analyzing Repeated Measures 


454  (5) 

Comparing the Means of Bivariate Responses in Two Groups 


459  (8) 

Onesample Analysis with Bivariate Responses 


467  (5) 


472  (2) 


474  (1) 


474  (9) 

Exploratory Tools for Summarizing Multivariate Responses 


483  (32) 


484  (4) 

Linear Combinations of Variables 


488  (2) 

Principal Components Analysis 


490  (7) 

Canonical Correlations Analysis 


497  (4) 

Introduction to Other Multivariate Tools 


501  (6) 


507  (2) 


509  (6) 

Comparisons of Proportions or Odds 


515  (23) 


516  (3) 

Inferences for the Difference of Two Proportions 


519  (6) 

Inference About the Ratio of Two Odds 


525  (4) 

Inference from Retrospective Studies 


529  (3) 


532  (1) 


533  (5) 

More Tools for Tables of Counts 


538  (26) 


539  (2) 

Population Models for 2 x 2 Tables of Counts 


541  (4) 


545  (3) 

Fisher's Exact Test: The Randomization (Permutation) Test for 2 x 2 Tables 


548  (4) 

Combining Results from Several Tables with Equal Odds Ratios 


552  (4) 


556  (1) 


557  (1) 


558  (6) 

Logistic Regression for Binary Response Variables 


564  (35) 


565  (3) 

The Logistic Regression Model 


568  (4) 

Estimation of Logistic Regression Coefficients 


572  (5) 

The DropinDeviance Test 


577  (6) 

Strategies for Data Analysis Using Logistic Regression 


583  (2) 


585  (4) 


589  (1) 


590  (1) 


591  (8) 

Logistic Regression for Binomial Counts 


599  (33) 


600  (4) 

Logistic Regression for Binomial Responses 


604  (1) 


605  (4) 

Inferences About Logistic Regression Coefficients 


609  (3) 


612  (3) 

Analysis of Moth Predation Data 


615  (5) 


620  (5) 


625  (2) 


627  (5) 

LogLinear Regression for Poisson Counts 


632  (27) 


633  (3) 

LogLinear Regression for Poisson Responses 


636  (3) 


639  (4) 

Inferences About LogLinear Regression Coefficients 


643  (1) 

ExtraPoisson Variation and the LogLinear Model 


644  (5) 


649  (2) 


651  (1) 


652  (7) 

Elements of Research Design 


659  (24) 


660  (1) 

Considerations in Forming Research Objectives 


660  (1) 


661  (3) 

Design Choices That Affect Accuracy and Precision 


664  (4) 


668  (3) 

Steps in Designing a Study 


671  (6) 

Related IssueA Factor of Four 


677  (1) 


678  (1) 


678  (5) 

Factorial Treatment Arrangements and Blocking Designs 


683  (24) 


684  (1) 


685  (2) 

Factorial Arrangement of Treatment Levels 


687  (10) 


697  (4) 


701  (1) 


702  (5) 
APPENDIX A Tables 

707  (17) 

A.1 Probabilities of the Standard Normal Distribution 


708  (2) 

A.2 Selected Percentiles of tDistributions 


710  (1) 

A.3 Selected Percentiles of ChiSquared Distributions 


711  (1) 

A.4 Selected Percentiles of FDistributions 


712  (8) 

A.5 Selected Percentiles of Studentized Range Distributions 


720  (4) 
APPENDIX B References 

724  (3) 
Answer Section 

727  (10) 
Index 

737  