Measurement in Health Behavior

Colleen Konicki Di Iorio, Ph.D., R.N., F.A.A.N, is a professor in the department of behavioral sciences and health education at Rollins School of Public Health, Emory University, and the associate editor of The Journal of Nursing Measurement. She has published numerous journal articles and book chapters on research and measurement methods in public health. Di Iorio is a contributor to the third edition of Health Education and Health Behavior from Jossey-Bass.

• Tables, Figures, and Exhibits xvPreface xxiThe Author xxv1 Introduction to Measurement 1Role of Measurement in Health Education and Health Behavior Research 1Brief History of Psychosocial Measurement 3Conceptualization of Measurement 6Reasons for Measuring Concepts 8Scales of Measurement 9Nominal Scale 9Ordinal Scale 11Interval Scale 12Ratio Scale 14Levels of Measurement and Statistics 15Major Concepts of Measurement: Reliability and Validity 16Reliability 16Validity 17Summary 172 Types of Measures 18Self-Report 19Interviews 19Questionnaires 20Journals and Diaries 22Response Scales 23Scaling Methods 24Visual Analog Scale 24Thurstone Scale 26Likert Scale 28Guttman Scale 29Semantic Differential Rating Scale 30Indexes 31Observations 33Biobehavioral Measures 33Electronic Measures 34Summary 353 Measurement Error 36Definition 37Classification of Measurement Error 38Random Error 38Systematic Error 39Measurement Error Factors 40Respondent Factors 40Response Sets 42Social Desirability 42Acquiescence and Nay-Saying 44End Aversion (Central Tendency) 44Positive Skew 45Halo 46Recall 46Instrument Factors 48Strategies to Reduce Errors on Self-Report Questionnaires 50Strategies to Reduce Errors During Interviews 51Situational Factors 51Measurement Rules 53Summary 534 Survey Development 54Definition 55Basic Principles of Survey Construction 55Purpose 55Objectives 56Respondents 59General Principles of Item Writing 59The Do’s of Item Writing 60The Don’ts of Item Writing 68Survey Format 70Survey Administration 72Summary 745 Knowledge Tests 75Test Construction 76State the Purpose of the Test 76State the Test Objectives 78Review Content 79Develop a Table of Test Specifications 79Domain-Sampling Model 80Types of Items 84Multiple-Choice Items 85True/False Items 90Item Analysis 92Item-Objective Congruency 92Average Congruency Percentage 98Difficulty Index 98Item Discrimination Index 101Summary 1016 Theory and Measurement 103Linking Measurement to Theory-Based Health Practice and Research 104Gibbs’s Model 106Theoretical and Operational Definitions 109Conceptualization Issues in Scale Development 110Survey Versus Scale 110Single-Item Versus Multiple-Item Scales 111Concept Selection 113Concept Analysis 114Identify Definitions and Uses of the Concept 114Identify Critical Attributes of the Concept 116Identify Dimensions of the Concept 117Identify Similar and Different Concepts 117Identify Antecedents and Consequences of the Concept 118Write a Model Case 118State the Variables 119Summary 1197 Item Writing and Scaling 121Item Development Process 122State the Theoretical Definition 123Identify Dimensions of the Concept 123Create a Content-Domain by Concept-Dimension Matrix 123Decide How Many Items to Include for Each Matrix Cell 124Write Items for Each Content-Domain by Concept-Dimension Cell 126Literature Review 126Qualitative Interviews 126Other Instruments 127Write Rules for Scale Scoring and Administration 128Summated Rating Scales 128Types of Response Options 128Number of Response Options 130Odd or Even Number of Categories 131Meanings of Response Option Adjectives or Adverbs 132Use of Adjectives, Adverbs, or Numbers, or Combinations Thereof 132Positively and Negatively Worded Items 133Scoring 133Summary 1358 Review of Statistical Concepts 136Basic Statistical Concepts 137Frequency Distribution 137Measures of Central Tendency 139Measures of Dispersion 139SPSS Commands 140Recode Negatively Worded Items Using SPSS 144Compute Total Scale Scores Using SPSS 145Review of Correlation 146Interpretation of the Correlation Coefficient 150Correlation Matrix 152Correlation Issues 152Causality 152Sample Size 153Group Differences 154Restriction of Range 154Variance 154Reporting Results of Correlation Analysis 156Analysis of Variance 157Definition and Use 157SPSS Commands for a One-Way ANOVA 158Interpreting a One-Way ANOVA 158Summary 1629 Fundamentals of Reliability 163Classical Test Theory 165Observed, True, and Error Scores 165Assumptions and Characteristics 167Reliability Coefficient 170Estimate of Reliability 172Calculation of Variance Due to the True Score 173Calculation of the Reliability Index 174Summary 17410 Reliability Assessment and Item Analysis 176Methods of Reliability Assessment 177Equivalence 177Stability 178Internal Consistency 181Split-Half 181Coefficient Alpha 184Cronbach’s Alpha 186Kuder-Richardson Formula 20 189Factors Associated with Coefficient Alpha 191Test Length and Interitem Correlation 191Test Adjustments to Increase Alpha 191Standards of Reliability 193Item Analysis 193Intrarater and Interrater Reliability 199Intraclass Correlation Coefficient 203Standard Error of Measurement 205Generalizability Theory 206Summary 21011 Validity 211Test Content 214Procedures 215Content Validity Index 218Face Validity 219Response Processes 220Procedures 221Think Aloud 221Verbal Probe 222Evaluation 222Relationships to Other Variables 224Criterion Validity 225Construct Validity 229Multitrait-Multimethod Matrix 233Validity Issues 235Summary 23612 Factor Analysis 237Exploratory Factor Analysis 238Definition 238Conceptual Basis 241How Factor Analysis Works 244Steps in Factor Analysis 244Basic Requirements for FA 246Initial Assessment 247Evaluation of the Matrix 248Evaluation of the Determinant 250Test for an Identity Matrix 251Tests of Sampling Adequacy 252Selection of the Type of Factor Analysis 253Initial Extraction 255Eigenvalues 256Communality 257Number of Factors 261Rotation of Factors 263Interpretation of Factors 267Confirmatory Factor Analysis 273Summary 27513 Item Response Theory 276Disadvantages of Classical Test Theory 277Item Response Theory Basics 278Polytomous Models 285Technical Issues 288Summary 289References 290Index 297