SOCIAL STATISTICS Németh, Renáta Simon, Dávid Created by XMLmind XSL-FO Converter. SOCIAL STATISTICS írta Németh, Renáta és Simon, Dávid Publication date 2011 Created by XMLmind XSL-FO Converter. Tartalom Introduction ........................................................................................................................................ v 1. Lecture 1 ......................................................................................................................................... 1 1. What is social statistics? Why do we need it? ....................................................................... 1 2. Interpretation pitfall I: Ecological fallacy ............................................................................. 1 3. Interpretation pitfall II: An empirical relationship does not imply causation ........................ 2 4. Interpretation pitfall III: Simpson‟s paradox ......................................................................... 2 2. Lecture 2 ......................................................................................................................................... 6 1. Role of statistics in social research ....................................................................................... 6 2. Levels of measurement ......................................................................................................... 8 3. Unit of analysis ..................................................................................................................... 9 3. Lecture 3 ....................................................................................................................................... 16 1. Frequency distributions for interval-ratio variables ............................................................ 16 4. Lecture 4 ....................................................................................................................................... 29 1. Motivation ........................................................................................................................... 29 2. Bar chart .............................................................................................................................. 30 3. Frequency polygon .............................................................................................................. 33 4. Stem-and-leaf plot ............................................................................................................... 34 5. How to lie with graphic presentations? ............................................................................... 36 6. Changing the scale .............................................................................................................. 37 7. Changing the range of the axis ............................................................................................ 37 8. Misleading 3D charts .......................................................................................................... 38 9. „Valid” charts ...................................................................................................................... 38 5. Lecture 5 ....................................................................................................................................... 39 1. Topics .................................................................................................................................. 39 2. Measures of central tendency .............................................................................................. 39 3. Mode ................................................................................................................................... 39 4. Characteristics of the mode ................................................................................................. 40 5. Median ................................................................................................................................ 41 5.1. Finding the median in sorted data (few observations) ............................................ 41 5.2. Finding the median in a frequency distribution (great number of observations) .... 43 6. Again about percentiles ....................................................................................................... 47 7. The mean ............................................................................................................................. 52 7.1. Properties of the mean ............................................................................................ 53 8. The shape of the distribution ............................................................................................... 54 9. Choosing the appropriate measure of central tendency ....................................................... 57 6. Lecture 6 ....................................................................................................................................... 58 1. Topics .................................................................................................................................. 58 2. Introduction ......................................................................................................................... 58 3. The index of qualitative variation (IQV) ............................................................................. 59 4. Range .................................................................................................................................. 61 5. Interquartile range ............................................................................................................... 62 6. Box plot ............................................................................................................................... 63 7. The variance and the standard deviation ............................................................................. 65 8. Choosing the appropriate measure of variability ................................................................. 68 9. Special measures of variability ........................................................................................... 69 9.1. Decile ratio ............................................................................................................. 69 9.2. Gini coefficient, Lorenz curve ................................................................................ 70 7. Lecture 7 Measuring the relationship between two variables 1: nominal and ordinal cases ......... 73 1. Introduction ......................................................................................................................... 73 2. The relationship of nominal or ordinal variables with crosstabs ......................................... 73 2.1. Dependent and independent variables .................................................................... 75 2.2. Example for investigating dependency ................................................................... 75 3. The existence of a relationship ............................................................................................ 76 4. Strength of relationship ....................................................................................................... 76 5. The direction of the relationship ......................................................................................... 76 6. Control: introducing one more variable .............................................................................. 78 iii Created by XMLmind XSL-FO Converter. SOCIAL STATISTICS 7. Controlling the relationship ................................................................................................. 78 7.1. An apparent relationship ......................................................................................... 78 7.2. The ‟intermediary‟ relationship .............................................................................. 79 7.3. Modifying the effect ............................................................................................... 81 8. Lecture 8: Relationship between nominal and ordinal variables: associational indices ............... 83 1. Introduction ......................................................................................................................... 83 2. PRE, proportional reduction of error ................................................................................... 83 2.1. Lambda‟s characteristics ........................................................................................ 84 3. Other associational indices for nominal variables ............................................................... 85 3.1. Revision Questions ................................................................................................. 87 3.2. For further thought .................................................................................................. 87 4. Associational indices of ordinal variables ........................................................................... 87 4.1. The characteristics of Somer‟s d: ............................................................................ 90 4.2. Another index: Spearman or rank correlation ......................................................... 90 4.3. Characteristics of Spearman (rank) correlation: ..................................................... 90 4.4. Revision Questions ................................................................................................