Table of Contents
Preface viii
Part I Introduction 1
Chapter 1 Terminology 2
Population, Sample, and Element 2
Descriptive vs. Inferential Statistics 2
Parameter vs. Statistic 2
Sampling Error vs. Selection Bias 3
Imprecision vs. Bias (Inaccuracy) 3
Validity vs. Reliability 4
Independent vs. Dependent Variables 4
Normal (Gaussian), Skewed, and Kurtotic curves 5
Multiplication and Addition Rules of Probability 7
Statistical Significance vs. Clinical Significance 8
Statistical Abnormality vs. Clinical Abnormality 8
Chapter 2 Mean, Median, and Mode 9
Mean 9
Median 9
Mode 9
What's Wrong Here? *#!! 11
Chapter 3 Range, Variance, and Standard Deviation 13
Range 13
Variance 14
Standard Deviation 14
Coefficient of Variation 15
Chapter 4 Kinds of Data 17
Nominal Data 17
Ordinal Data 17
Interval Data 17
Ratio Data 18
Part II Research Design 19
Chapter 5 Kinds of Studies 20
Randomized Control Studies 20
Matching Studies 20
Stratified Randomization Studies 21
Blind Studies 21
Prospective (Cohort; Longitudinal) Studies 21
Retrospective (Case-control) Studies 23
Cross-sectional (Prevalence) Studies 24
Experimental vs. Observational Studies 24
Case Series and Case Reports 25
Meta-analysis 25
Crossover, Between-subjects, and Within-subjects Studies 26
Therapeutic Trials 26
Chapter 6 Kinds of Graphs 27
Bar Graphs (Bar Charts) 27
Tables 28
Histograms 28
Line Graphs 29
Cumulative Frequency Curves 30
Box-and-Whiskers Plots 31
Stem-and-Leaf Plots 32
Scattergrams 33
Survival Curves 33
Chapter 7 Hypothesis Testing 36
The Null and Alternative Hypotheses 36
Rejecting the Null Hypothesis 37
Part III Statistical Tests 39
Parametric vs. Nonparametric Tests 39
Chapter 8 Descriptive Statistics 40
The Z-score 40
Chapter 9 Inferential Statistics 43
Confidence Intervals vs. Hypothesis Testing and P-values 43
Chapter 10 Standard Error of the Mean (SEM) 46
The Central Limit Theorem 46
Standard Error of the Mean 47
Chapter 11 The t-Test 49
The Meaning of the t-Test 49
Comparing Two Samples 49
Chapter 12 One-Tailed Vs. Two-Tailed Studies 52
The Two-Tailed Test 52
The One-Tailed Test 53
Chapter 13 P-Ing (PEE-ING) All Over the Place 56
Chapter 14 Type I and Type II Errors 58
Type I and Type II Errors 58
Power 59
Effect Size 60
Bayesian Thinking 61
Calculation of Sample Size 62
Chapter 15 ANOVA (Analysis of Variance) 64
ANOVA and F-ratio 64
MANOVA and ANCOVA 66
Chapter 16 Correlation and Regression 68
Correlation Techniques 68
Correlation Does Not Mean Causation 70
Criteria of Causality 71
Regression 72
Kinds of Regression Analysis 73
Regression to the Mean 74
Chapter 17 Nonparametric Tests 75
Chi-Square (X2) Goodness-of-Fit Test 75
Nonparametric Tests That Use Ranking 78
Nonparametric Tests That Do Not Use Ranking 79
Chapter 18 Epidemiological Tests 80
Incidence vs. Prevalence 80
Mortality, Morbidity, and Case Fatality 81
Absolute Risk vs. Relative Risk (RR) 81
Odds and Odds Ratio (Relative Odds) 82
Absolute Risk Reduction (Attributable Risk) vs. Relative Risk Reduction 83
Number Needed to Treat (NNT) 84
Number Needed to Harm (NNH) 84
Sensitivity vs. Specificity 85
Positive and Negative Predictive Values 87
Part V Are the Research Conclusions Correct? 89
Chapter 19 What's Wrong Here? 90
Who Says So? 90
How Does the Researcher Know? 90
What's Missing? 91
Did Someone Change the Subject? 94
Does It Make Sense? 95
Appendix A The Z table 96
Appendix B The t table 97
Appendix C The Chi-Square Table 98
References 99
Index 101
