Data Collection

In Statistics, there is

  • a research question about the target population
  • and we need to answer it based on some data
  • how to get the data?


  • Typically cannot get the data for the entire population
  • Can take a fraction of this data - this is called Sampling


There are several types of data collection:

  • Observational Studies - monitor and record
    • sufficient to show association
    • not sufficient to show causation
  • Statistical Experiments - conduct an experiment and collect the data
    • sufficient to show causation when the experiment is designed carefully