CHAPTER 25
Importing and Cleaning Data
Data is everywhere. For example, if you run a website, you're collecting data continually, and you may not even know it. Every visit to your site generates information that is stored in a file on your server. This file contains lots of useful information, if you take the time to examine it.
That's just one example of data collection. Virtually every automated system collects data and stores it. Most of the time, the system that collects the data is also equipped to verify and analyze the data—but not always. And, of course, data is also collected manually. A nonautomated telephone survey is a good example.
Excel is a good tool for analyzing data, and it's often used to summarize the information and display it in the form of tables...
