Coursera Basic Statistics

Notes from Coursera Basic Statistics.

Data and visualization

Descriptive Statistics?

Variables - characteristics of something or someone Cases - the something of someone being measured Observation - a variable meausurement for a particular case

Levels of Measurement

Categorical

Nominal - There’s some difference the values, e.g. City of Birth Ordinal - Values can be ordered, e.g. 1st, 2nd place

Quantitative

Interval - Values have intervals, e.g. Age Ratio - Value has meaningful zero point, e.g. Height

Ways to present data

Data matrix - a matrix with cases on the y-axis and variables on the x-axis. Values within the matrix are observations, e.g:

Person Age Weight Eye Color
Bob 42 210 Blue
Alice 24 120 Brown

Frequency Table - One way to summarize data matrix, e.g.:

Eye Color Percent
Blue 14
Brown 28

Charts

Pie Chart or Bar Graph for categorical data Dot Plot or Histogram for quantitative