SPSS Statistics For Dummies, 4th Edition

Chapter 1

Introducing SPSS

IN THIS CHAPTER

Considering the quality of your data

Communicating with SPSS

Seeing how SPSS works

Finding help when you’re stuck

A statistic is a number, but it's a special kind of number. A statistic is a measurement of some sort. It’s fundamentally a count of something — occurrences, speed, amount, or whatever. A statistic is calculated using a sample. In a sense, a sample is the keyhole you have to peer through to see the population, which is what you’re trying to understand. The value at the population level — the average height of an American male, for instance — is called a parameter. Unless you’ve got all the data there is, and you’ve collected a census of the population, you have to make do with the data in your sample. The job of SPSS is to calculate. Your job is to provide a good sample. Together you try to understand the population even though all you have is a sample.

In this chapter, we discuss the importance of having accurate, reliable data, and some of the implications when this is not the case. We talk also about how best to organize ...