Chapter 5 Random Variability

Up until this point, we have thought about

1. Data collection process (sampling and study design) and Data Quality (issues of bias)
2. Data visualization (the first step of any data analysis)
3. Modeling (to explain observed variation and provide predictions)

Throughout the past three chapters, we have also sprinkled in the idea that the sample we observe is just one random representation of the true population or phenomenon. Therefore, any statistic, any numerical summary of the sample, would be an estimate the true numerical summary of the population (which we refer to as the corresponding unknown parameter).