ST 260 Lecture Notes - Lecture 1: Ticker Tape

• School: University of Alabama
• Department: Statistics
• Course: ST 260
• Professor: Bradley Casselman

Document Summary

Definition: variable: any measurable characteristic of a person or thing. In a date set, be aware of the: types of variables and the measurement scale. Types & scales: categorical/qualitative nominal, ordinary, binary, quantitative discrete, continuous. Scales of measurement: nominal each value is a category, ordinal order has a meaning, ratio true absolute zero. Rule of thumb: if averages or differences have meaning, a variable is quantitative: ex. weight, height, income, age. Types of quantitative variables: discrete listable values with gaps between them. Note: not necessarily integers and may be an infinite number of values: continuous any value in an interval can occur. Rule of thumb: a variable that classifies people or things, is qualitative or categorical: ex. sex, political affiliation, race, country of origin. Types of qualitative variables: nominal (cid:374)u(cid:373)(cid:271)ers are used to (cid:862)name(cid:863) (cid:272)ategories. Ex. football jersey number: ordinal the categories have a natural ordering. Ex. course grade: binary t(cid:449)o (cid:272)ategories (cid:894)usually assig(cid:374)ed (cid:448)alues of (cid:862)(cid:1004)(cid:863) or (cid:862)(cid:1005)(cid:863)(cid:895)