Basics of Statistics

At its heart, statistics is a process that we use to describe, analyze, and make decisions from information.

Figure 1.2: The process of statistics

In section 1.1 we will discuss this process and ways to classify data. In section 1.2 we will focus on methods used to obtain data from samples. In section 1.3 we discuss observational studies and experimental design, two powerful methods we can use to obtain data. Sources of error in statistics are discussed in section 1.4.

By the end of this chapter, you will be able to

•Describe the process of statistics.

•Categorize variables and data as Qualitative or Quantitative, and as Nominal, Ordinal, Discrete or Continuous.

•Identify when data is from a census or sample and distinguish between parameters and statistics.

•Identify the methodologies used to obtain data and describe how and when they are best utilized.

•Determine whether data comes from an observational study or a designed experiment and discuss the differences between them.

•Identify common errors in sampling that lead to biased data and incorrect results.

•Determine when an error is a "sampling error" and when it is a "non-sampling error" and describe each type of error.