displaying categorical data

what types of visuals are used (display categorical data)

pie charts or bar graphs

what makes a graph misleading

vertical axis does not start at zero

marginal relative frequency (outside)

gives percent/proportion of individuals that have specific value for one categorical value

joint relative frequency (inside)

gives percent/proportion of individuals that have a specific value for one categorical variable and specific value for another categorical variable

association

knowing value of one variable helps us predict the value of others

• look for bar heights that are different

symmetric

mirror image

skewed right

right side of graph is much longer than left (tail right & bulk on left)

skewed left

left side is much longer than right (tail left, bulk right)

unimodal

single peak

bimodal

two distinct clusters & peaks