Statistics

Descriptive Statistics : Provides statistical information about whole sets of data or populations.

Inferential Statistics : Provides statistical information about a dataset represented by a sample. It does so through a sample of the same population.

Collected Data types

• Time Series : Data collected over a period of time. (eg: same guy at different age)
• Cross Sectional : Data collected at one point in time. (eg: different guys at one point in time)
• Pooled : Combination of cross sectional and Time series data. (eg: different guys at different age)
• Longitudinal / Panel : Same as pooled

Data Scale

• Quantitative
  • Discrete : Integers
  • Continuous : Real Numbers
• Categorical
  • Ordinal scale : Natural order exists (eg. high, medium, low)
  • Nominal scale : No natural order (eg. Names)

Sampling

• Simple Random Sample : Every element in the population has an equal probability of being included in the sample i.e. a sample with no bias.
• Stratified Sampling : The population is divided into separate groups called strata. Then a probability sample is drawn from each group.
• Cluster Sampling : The total population is divided into clusters and a simple random sample of the groups is selected.