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Preface | |
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Introduction | |
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Overview | |
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Statistics | |
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Variables and Variability | |
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Preparing Data for Analysis | |
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Putting It All Together | |
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Key Terms | |
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References | |
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Problems | |
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Research Methodology: A Primer | |
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Overview | |
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The Importance of Good Research Design | |
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Statistical Analysis and the Big Picture | |
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Research Ethics | |
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Basics of Research Design | |
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Experimental and Correlational Investigations | |
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Two Basic Questions | |
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Notational System | |
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Types of Designs | |
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Pre-Experimental Designs | |
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One-Shot Case Study | |
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The One-Group Prtest-Posttest Design | |
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Static Group Comparison Design | |
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Experimental versus Statistical Control | |
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More on Internal Validity | |
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Possible or Probable? | |
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True Experimental Designs | |
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Pretest-Posttest Control Group Design | |
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Posttest-Only Control Group Design | |
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External Validity | |
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Quasi-Experimental Designs | |
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Time Series Design | |
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Nonequivalent Control Group Design | |
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Measurement Issues | |
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Scales of Measurement | |
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Reliability and Validity | |
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Tests and Self-Report Measures | |
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Desirable Characteristics of Standardized Tests | |
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Test Reliability | |
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Test Validity | |
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Other Characteristics of Standardized Tests | |
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Putting It All Together | |
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Key Terms | |
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References | |
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Problems | |
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Organizing and Displaying Data | |
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Overview | |
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Why Organize and Display Data? | |
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Ways of Organizing Data | |
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Data Screening | |
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Organizing the Data | |
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Ranking | |
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Percentages and Percentiles | |
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Uses of Percentiles and Percentile Ranks | |
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Grouping the Data | |
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Selecting a Class Interval | |
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Estimating Percentiles and Percentile Ranks from Grouped Frequency Distributions | |
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Grouping: Advantages and Disadvantages | |
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Crosstabulation | |
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Displaying the Data | |
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What Exactly Are Visual Displays? | |
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Plots and Charts | |
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Putting It All Together | |
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Key Terms | |
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References | |
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Problems | |
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Descriptive Statistics | |
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Overview | |
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Why Summarize the Data? | |
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Summation Notation | |
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Measures of Central Tendency | |
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The Basics | |
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Selecting a Measure of Central Tendency | |
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Other Measures of Central Tendency | |
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Shapes of Distributions | |
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Measures of Dispersion | |
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The Basics | |
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Moments About the Mean | |
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Measures of Bivariate Relationship | |
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Putting It All Together | |
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Measures of Central Tendency | |
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Shapes of Distributions | |
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Measures of Dispersion | |
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Moments About the Mean | |
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Measures of Bivariate Relationship | |
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Key Terms | |
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References | |
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Problems | |
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Building Blocks of Inferential Statistics: Probability, Chance, Variability, and Distributions | |
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Overview | |
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Probability: The Foundation of Inferential Statistics | |
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Probability | |
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Interpreting the Findings | |
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Approaches to Probability | |
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The Role of Probability Theory in Inferential Statistics | |
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Samples and Populations | |
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Variability | |
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The Shape of Chance Variability: More Pieces of the Puzzle | |
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The Binomial Distribution | |
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Properties of the Normal Distribution | |
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Binomial Distribution: The Normal Approximation | |
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Normal Distribution: Some Other Important Properties | |
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Areas Under the Normal Distribution | |
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The Standard Normal Distribution and z-Scores | |
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Other Issues in Understanding and Using the Normal Distribution | |
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T-Scores | |
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Putting It All Together | |
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The Binomial Distribution | |
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Properties of the Normal Distribution | |
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T-Scores | |
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Key Terms | |
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References | |
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Problems | |
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Sampling Distributions | |
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Overview | |
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Basic Concepts in Statistical Inference | |
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Key Terms in Statistical Inference | |
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Using Sample Statistics to Estimate Population Parameters | |
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Desirable Properties of Estimators | |
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Good Estimators | |
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Formulas for Samples, Populations, and Population Estimators | |
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Sampling Distributions | |
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Interval Estimation of the Mean | |
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Hypothesis Testing | |
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Hypothesis Testing Using the z-Test | |
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Interval Estimation of the Mean Difference | |
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Putting It All Together | |
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Formulas for Samples, Populations, Population Estimators, Sampling Distributions, and Sampling Distribution Estimators | |
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Using the Sampling Distribution for Hypothesis Testing | |
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Key Terms | |
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References | |
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Problems | |
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Statistical Issues in Hypothesis Testing | |
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Overview | |
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Steps in Hypothesis Testing | |
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State the Null and Alternative Hypotheses | |
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Select Alpha: The Probability Value for Significance Testing | |
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Select the Appropriate Test Statistic | |
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Compute the Calculated Value of the Test Statistic | |
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Find the Critical Value of the Test Statistic | |
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Compare the Calculated and Critical Values | |
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An Important Caveat on the Six Steps in Hypothesis Testing | |
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Devil's Advocate Example | |
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z-Test Interval Estimation | |
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One-Sided Confidence Intervals | |
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Statistical Power | |
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The Alternative Distribution | |
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Steps in Estimating Power | |
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Interpretation and Guidelines for Acceptable Statistical Power | |
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Estimating the Power of Your Research | |
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Ways to Increase Statistical Power | |
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Other Considerations | |
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Effect Size and Practical Importance | |
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The Effect Size | |
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Effect Size Calculation for the Devil's Advocate Scenario | |
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Effect Sizes and Power | |
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Is John Correct? | |
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Guidelines for Using Statistics | |
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Putting It All Together | |
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Key Terms | |
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References | |
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Problems | |
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Testing the Difference Between Two Independent Groups: The t-Test | |
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Overview | |
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What's Wrong with the z-Test? | |
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Review and Application of the z-Test | |
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The Contribution of William Gosset | |
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The Separate Variance Model t-Test | |
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Effect of Sample Size on the Critical Value | |
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Degrees of Freedom | |
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Finding the Correct Critical Value | |
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Exact Probabilities | |
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Confidence Intervals | |
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Effect Sizes Calculations and Power | |
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The Drill Press Example | |
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The Pooled Variance Model t-Test | |
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Pooled Standard Error | |
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Pooled Variance Model t-Test | |
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Confidence Intervals Based on the Pooled Variance Approach | |
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Effect Size Calculations Based on the Pooled Variance Approach | |
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Comparison of Two Approaches | |
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Underlying Assumptions | |
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The Variability Within Each Group Should Be Normally Distributed | |
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Each Data Point, or Score, Should Be Independent of Every Other Data Point | |
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The Variances of the Two Groups Should Be Equal or Homogeneous | |
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Choosing Between the Separate and Pooled Variance Models | |
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Guidelines for Choosing Between the Two Models | |
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Putting It All Together | |
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Key Terms | |
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References | |
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Problems | |
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Testing the Difference Between Two or More Independent Groups: The Oneway between-Groups Analysis of Variance | |
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Overview | |
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Omnibus Tests of Significance | |
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Multilevel Independent Variables | |
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Specific or General Hypotheses? | |
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Partitioning Variability | |
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The Simple Mathematics of Variance Partitioning | |
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Total Variability | |
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Between-Groups Variability | |
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Within-Groups Variability | |
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The F-Test | |
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From Sums of Squares to Variances | |
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Mean Squares | |
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F as a Ratio of Variances | |
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Reporting ANOVA Results | |
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Underlying Assumptions | |
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Assumptions | |
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Effects of Assumption Violations | |
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Effect Size Calculations and Power | |
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Effect Size Calculations for Two Groups | |
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Using R[superscript 2] and f to Estimate the General Effect Size | |
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Another Method for Estimating General Effect Sizes: [omega superscript 2] | |
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Power | |
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Putting It All Together | |
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Key Terms | |
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References | |
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Problems | |
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A Proof that t[superscript 2] = F | |
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Testing the Difference Between Two or More Independent Groups: Multiple Comparisons | |
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Overview | |
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Multiple Comparisons Basics | |
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What Is a Comparison? | |
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When Multiple Comparisons Should Be Avoided | |
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Why Use Multiple Comparisons? | |
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Planned Comparisons (Also Known as A Priori Comparisons) | |
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Post Hoc Comparisons (Also Known as A Posteriori Comparisons) | |
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Planned Comparisons | |
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Specific Hypotheses | |
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Rules for Evaluating Planned Comparisons | |
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Symbol System | |
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Valid Planned Comparisons | |
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Independence of Planned Comparisons | |
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Statistically Evaluating Planned Comparisons | |
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Dealing with Variance Heterogeneity | |
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Post Hoc Comparisons | |
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Conceptual Unit for Error Rate | |
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Tukey's HSD | |
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Scheffe's S Method | |
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Putting It All Together | |
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Planned Comparisons | |
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Post Hoc Comparisons | |
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Key Terms | |
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References | |
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Problems | |
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Analyzing More Than a Single Independent Variable: Factorial Between-Groups Analysis of Variance | |
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Overview | |
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Factorial Designs | |
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The Simplest Case: A 2 [times] 2 Factorial | |
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A Bit More on Main Effects and Interactions | |
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Factorial Analysis of Variance | |
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Subdividing Between-Groups Variability | |
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Omnibus Hypotheses | |
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The General Linear Model | |
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Partitioning Variability in Twoway ANOVA | |
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From SS to MS to F | |
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Twoway Factorial ANOVA: Computational Example | |
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Other Issues in Factorial ANOVA | |
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Multiple Comparison and Simple Effect Tests | |
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Overview | |
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Planned Orthogonal Comparisons Procedures for Factorial ANOVA | |
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Post Hoc Comparisons for Factorial ANOVA | |
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Tests of Simple Effects | |
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Probing Significant Simple Effects | |
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Putting It All Together | |
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Partitioning Variability in Twoway ANOVA | |
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Key Terms | |
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References | |
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Problems | |
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Within-Groups Designs: Analyzing Repeated Measures | |
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Overview | |
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Basics of Within-Groups Designs | |
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Designs with a Single Treatment | |
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Designs with More Than a Single Treatment | |
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Other Uses of Within-Groups Analyses | |
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The Advantages of Within-Groups Designs | |
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The Disadvantages of Within-Groups Designs | |
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Counterbalancing | |
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Correlated or Dependent Samples t-Test | |
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Review of the Independent Samples t-Test | |
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Correlated Samples t-Test: Raw Score Method | |
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Correlated Samples t-Test: Individual Difference Score Method | |
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Effect Size and Power | |
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Oneway Within-Groups ANOVA | |
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Underlying Logic | |
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Analyzing the Data with and Without the Dependencies | |
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Computational Procedures for the Oneway Within-Groups ANOVA | |
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Assumptions and Assumption Violations | |
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Multiple Comparisons | |
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Effect Size and Power | |
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Mixed Designs | |
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Underlying Logic | |
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Computational Procedures for the Twoway Mixed Design ANOVA | |
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Putting It All Together | |
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Correlated Samples t-Test | |
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Oneway Within-Groups ANOVA | |
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Mixed Designs | |
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Key Terms | |
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References | |
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Problems | |
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Determining the Relationship Between Two Variables: Correlation | |
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Overview | |
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Correlation Basics | |
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Similarities with Other Research Situations | |
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Differences from Other Research Situations | |
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Correlation and Causation | |
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Oneway ANOVA versus Correlation: What Is the Difference? | |
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Correlation: Scatterplots | |
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Creating a Scatterplot | |
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Interpreting a Scatterplot | |
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The Pearson Product Moment Correlation | |
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Describing Linear Relationships | |
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Range of Values | |
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The Contribution of Karl Pearson | |
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Computing the Pearson Product Moment Correlation | |
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The z-Score Method | |
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The Covariation Method | |
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Inferential Uses | |
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Hypothesis Testing | |
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Calculated and Critical Values | |
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Parental Performance Example | |
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Underlying Assumptions | |
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Confidence Intervals | |
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Skewed Distribution of r | |
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Fisher's Transformation | |
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Estimating Confidence Intervals | |
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The Value of Confidence Intervals | |
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Strength of Association | |
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Coefficient of Determination | |
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Parental Performance Example | |
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Derivatives of the Pearson Product Moment Correlation | |
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Some Cautions and Limitations | |
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Restriction of Range | |
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Attenuation Due to Measurement Error | |
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Departures from Linearity | |
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Outliers | |
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Dealing with Missing Values | |
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Putting It All Together | |
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Computational Procedures | |
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Cautions and Limitations | |
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Key Terms | |
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References | |
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Problems | |
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Determining the Relationship Between Two Variables: Simple Linear Regression | |
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Overview | |
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Some Simple Regression Basics | |
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What Is the Difference Between Correlation and Regression? | |
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Lines and Plots | |
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Perfect Prediction | |
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Slope | |
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Intercept | |
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Imperfect Prediction | |
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The Best-Fit Straight Line | |
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Relationship Between the Correlation Coefficient (r) and the Regression Coefficient (b') | |
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The z-Score Method for Determining the Regression Equation | |
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Statistical Tests for Simple Regression | |
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Partitioning Variability | |
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From Sums of Squares to the F-Test | |
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Testing Significance Using the t-Test | |
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Other Issues in Simple Linear Regression | |
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Confidence Intervals | |
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Strength of Association | |
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Power | |
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Underlying Assumptions | |
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Using Standardized Residuals to Check the Data | |
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Putting It All Together | |
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Key Terms | |
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References | |
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Problems | |
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Dealing with More Than a Single Predictor Variable: Multiple Linear Regression | |
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Overview | |
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The Logic of Multiple Linear Regression | |
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The Multiple Regression Equation | |
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Uncorrelated versus Correlated Predictors | |
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The Multiple Regression Equation and Tests of Significance | |
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Components of the Multiple Regression Equation | |
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Tests of Significance | |
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The Incremental Approach to Multiple Linear Regression | |
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Hierarchical Regression | |
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Stepwise Regression | |
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Special Issues in Multiple Linear Regression | |
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Outliers | |
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III-Conditioned Data | |
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Adjusted R[superscript 2] | |
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Putting It All Together | |
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The Multiple Regression Equation | |
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Tests of Significance: Simultaneous Approach | |
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Incremental Approach to Multiple Regression | |
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Special Issues in Multiple Linear Regression | |
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Key Terms | |
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References | |
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Problems | |
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Nonparametric Statistical Tests | |
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Overview | |
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Why Nonparametric Statistical Tests? | |
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Assumptions and Assumption Violations | |
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Scales of Measurement | |
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Advantages and Disadvantages | |
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Chi-Square and the Analysis of Nominal Data | |
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Requirements for Using Chi-Square | |
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Frequencies and Categories | |
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About Chi-Square | |
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Goodness of Fit | |
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Test of Independence | |
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Dealing with Small Sample Sizes | |
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Multiple Comparisons | |
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Measures of Association or Effect Size | |
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The Analysis of Ordinal Data | |
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Mann-Whitney U-Test | |
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Kruskal-Wallis Oneway ANOVA H-Test | |
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Correlated Samples | |
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Putting It All Together | |
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Chi-Square and the Analysis of Nominal Data | |
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The Analysis of Ordinal Data | |
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Key Terms | |
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References | |
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Problems | |
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Areas Under the Standard Normal Curve Corresponding to Given Values of z | |
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Table of Random Numbers | |
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Critical Values of the t-Distribution | |
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Critical Values of the F Distribution | |
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Power Tables for the Analysis of Variance | |
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Percentage Points of the Studentized Range Statistic | |
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Values of the Correlation Coefficient Required for Different Levels of Significance When H[subscript 0]: p = 0 | |
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Values of Fisher's z[subscript F] for Values of r | |
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Upper Percentage Points of the Chi-Square Distribution | |
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Critical Values of Mann-Whitney's U | |
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Critical Values of Wilcoxon's T | |
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Answers | |
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Index | |