POLS 3650 Lecture Notes - Lecture 4: Bar Chart, Line Graph, Frequency Distribution

• School: University of Guelph
• Department: Political Science
• Course: POLS 3650
• Professor: Edward Koning

Document Summary

In compiling a data set, we inevitably encounter the problem of missing data 9: or empty cells, two types of missing data in survey data. User-missing: data are missing because the respondent gave no answer or no useful answer. System-missing: data are missing because the question has not been asked to the respondent. The purpose of visualization: the first thing we do after data collection and preparation is visualization: presenting the data in tables and figured. Helps identify obviouc measurement or coding mistakes. Helps identify cases with extreme values (outliers) Tells us how suited our data are for analysis. Types of visualization: two types of visualizations. Frequency distributions (bivariate, multivariate, crosstabs, summary tables of results) Bar charts for continuous variables, we use a subtype of a bar chart, called a histogram in histograms, there is no space between the bars. Nominal and ordinal variables: base yourself on the raw frequency distribution or some meaningful typology.