However, secondary analysis typically refers to the re-analysis of quantitative data rather than text. In our modern world there is an unbelievable mass of data that is routinely collected by governments, businesses, schools, and other organizations. Much of this information is stored in electronic databases that can be accessed and analyzed. In addition, many research projects store their raw data in electronic form in computer archives so that others can also analyze the data. For example, you might join crime data with census information to assess patterns in criminal behavior by geographic location and group.
Secondary analysis has several advantages.
First, it is efficient. It makes use of data that were already collected by someone else. It is the research equivalent of recycling. Second, it often allows you to extend the scope of your study considerably. In many small research projects it is impossible to consider taking a national sample because of the costs involved.