# 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