LFS 252 Lecture Notes - Bar Chart, Unimodality, Categorical Variable
Document Summary
Suggest confounding variables prevent us from inferring causation. People who eat garlic may also eating higher level of food affecting the outcomes. Numerical and categorical variables: data is observation that you or someone else records, data is numbers- measurement e. g. weight, height, data can be nonnumeric : eye color , drinking or not. A variable is a characteristic of people or things e. g. weight, eye color. Population is the collection of all data values. A sample is a subset of the population. > a sample is used to get a partial, representing a portion of a big group. Categorical sometimes will contain numbers, but it still counts as categorical data. Categorical data in two- way tables : counts and frequency. Designing experiments: observation study: uses group that are already created and recorded the difference. We can only say the treatment and outcomes are associated instead of causation.
