Chapter 3 Why we use statistics

As described in the introduction the goal of this book is to integrate genetics, statistics and programming.

Statistics provide serve two complementary purposes. We can use them to:

• provide summaries of data
• make inferences from data

In the context of human heredity these two purposes are used all the time. For example,

• provide summaries of data
  • determine the mean level of expression of a gene
  • determine the distribution of normal body weights
• make inferences from data
  • test whether patients who take a drug differ from those who don’t
  • test whether a specific variant is associated with a disease

In this book, we will look at using statistics for both summarizing data and making inferences based on a sample from a population.