Filtering Data

Along with summarizing and trending, filtering can be an extremely effective analysis technique. For example, looking over a page or two of stock reports in the newspaper can be time-consuming, if not downright frustrating. If you own 20 or 50 stocks, for example, you can’t gather results for just the stocks you own (at least without a highlighter pen or scissors!). As another example of filtering, most e-mail programs allow you to automatically delete or move unwanted e- mail messages that meet specific conditions.

The benefits of summarizing data apply to filtering data as well, but filtering differs from summarization in that filtering displays only individual records or fields that match specific conditions. A summary does not necessarily indicate how many records or fields contributed to the final summarized value.

While many filters involve only one condition, most filters applied to business data involve several fields at once. All the data analysis software applications described in this book handle a variety of data filtering tasks.

Your Turn

This exercise demonstrates how you can display data records that match specific conditions.

1. In the CustServ.xls file (located in the Chap02 folder), on the Original Data worksheet, determine how many rows contain a value less than 4 in columns C through G.

2. Next examine the Filtered By <4 Scores worksheet, shown in Figure 2-5, and compare the number of rows you came up with in the previous step.

   
   Figure 2-5: Records with all average customer service scores less than 4.

Filtering allows you to select records that match specific conditions.