Quantitative data analysis using SPSS : an introduction for health and social science

Contents Introduction 1 1 A questionnaire and what to do with it: types of data and relevant analyses 5 1.1 The questionnaire 5 1.2 What types of analyses can we perform on this questionnaire? 7 1.2.1 Descriptive statistics 7 1.2.2 Relationships and differences in the data 13 1.3 Summary 16 1.4 Exercises 17 1.5 Notes 18 2 Coding the data for SPSS, setting up an SPSS database and entering the data 19 2.1 The dataset 19 2.2 Coding the data for SPSS 20 2.3 Setting up an SPSS database 21 2.3.1 Defining the variables 22 2.3.2 Adding value labels 25 2.4 Entering the data 27 2.5 Exercises 28 2.6 Notes 31 3 Descriptive statistics: frequencies, measures of central tendency and illustrating the data using graphs 33 3.1 Frequencies 33 3.2 Measures of central tendency for interval variables 38 3.3 Using graphs to visually illustrate the data 41 3.3.1 Bar charts 41 3.3.2 Histograms 45 3.3.3 Editing a chart 46 3.3.4 Boxplots 50 3.3.5 Copying charts and tables into a Microsoft Word document 52 3.3.6 Navigating the Output Viewer 56 3.4 Summary 57 3.5 Ending the SPSS session 58 3.6 Exercises 58 3.7 Notes 60 4 Cross-tabulation and the chi-square statistic 61 4.1 Introduction 61 4.2 Cross-tabulating data in the questionnaire 61 4.3 The chi-square statistical test 63 4.4 Levels of statistical significance 67 4.5 Re-coding interval variables into categorical variables 69 4.6 Summary 73 4.7 Exercises 73 4.8 Notes 75 5 Correlation: examining relationships between interval data 77 5.1 Introduction 77 5.2 Examining correlations in the questionnaire 77 5.2.1 Producing a scatterplot in SPSS 78 5.2.2 The strength of a correlation 80 5.2.3 The coefficient of determination 82 5.3 Summary 83 5.4 Exercises 84 5.5 Notes 85 6 Examining differences between two sets of scores 86 6.1 Introduction 86 6.2 Comparing satisfaction ratings for the two counsellors 88 6.2.1 Independent or related samples? 88 6.2.2 Parametric or non-parametric test? 88 6.3 Comparing the number of sessions for each counsellor 95 6.4 Summary 100 6.5 Exercises 101 6.6 Notes 102 7 Reporting the results and presenting the data 103 7.1 Introduction 103 7.2 Structuring the report 103 7.3 How not to present data 107 Concluding remarks 109 Answers to the quiz and exercises 110 Glossary 130 References 133 Index 135