Statistical Sciences 2244A/B Chapter Notes - Chapter 1-2: Exploratory Data Analysis, Qualitative Property, Categorical Variable
21 Sep 2016
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Individuals: objects described by a set of data. Variable: any characteristic of an individual, different values for different individuals. Categorical variable/ qualitative data: places an individual into one of several groups or categories: nominal: purely qualitative and cannot be ranked, ordinal data: data can be ranked, e. g. strongly agree, agree, etc. Exploratory data analysis: examine each variable itself, then move to study relationship between variables, graphs. Distribution: what values a variable taken on and how often it is those values. In this course: when n is odd include median in observations. In this course: when n is even do not include the median, the middle between 2 values. Good for comparing data, but less data than a histogram. Any values not between is considered an outlier. Modified boxplots: display any values outside of 1. 5 x iqr interval by a star. Error bars: error bars shown as the standard deviation of each group.
