1. Presenting Data Descriptive Statistics

2. Chapter- Presentation of Data Mona Kapoor

3. Nominal Level No order, just a name Can report –Mode –Bar Graph –Pie Chart

4. Ordinal Level Rank order only Can Report –Mode –Median –Percentiles –Histograms and Pie Charts

5. Interval/Ratio Level Equidistant Can Report –Mode, Median, Mean –Standard Deviation –Percentiles –Frequency curves, Histograms

6. Univariate Data Good to start at the univariate level Univariate: one variable at a time –Investigate the responses –Assess usability for the rest of the analysis

7. Frequency Table Shows how often each response was given by the respondents Most useful with nominal or ordinal –Interval/ratio has too many categories In Minitab, Select: Stat>Tables>Tally

8. Charts and Graphs Use a bar graph or pie chart if the variable has a limited number of discrete values –Nominal or ordinal measures Histograms and frequency curves are best for interval/ratio measures In Minitab, Select: Graph > (and then type)

9. Normal Curve The normal curve is critical to assessing normality which is an underlying assumption in inferential statistical procedures –And in reporting of results Kurtosis: related to the bell-shape Skewness: symmetry of the curve –If more scores are bunched together on the left side, positive skew (right) –If most scores are bunched together on the right side, negative skew

10. Normal Curve To get a statistical summary, including an imposed normal curve in Minitab: Select: Stat > Basic Statistics > Display Descriptive Statistics > Graph > Graphical Summary

11. Measures of Central Tendency Mode: most frequently selected –Bimodal = two modes –If more than two modes, either multiple modes or no mode Median: halfway point –Not always an actual response Mean: arithmetic mean

12. Percentiles The median is the 50 percentile A percentile tells you the percentage of responses that fall above and below a particular point Interquartile range = 75 th percentile – 25 th percentile –Not affected by outliers as the range is