Example: Fleetwood Area Public Library - Checkouts by Patron Code
Notes:
- To create a Visualization, you need some data.
- The source of the data for this Viz is the library's Integrated Library System, Polaris.
- You can download reports from the ILS into Microsoft Excel spreadsheets
- The format of the spreadsheet must be transformed into the form that Tableau requires:
- The data should be in raw form, without empty rows, totals, formulas, etc
- Excel power users will have more and better ways to transform their spreadsheets than are described here.
- Make sure that each row refers to only one piece of data. For example, change this table, which has three data points for score (one each for Math, English and Science):

- Into this table, with only one data point for score

- The first row in your spreadsheet should contain field headers, and it is the only row that should contain them
- There should be no blank cells
- Remove aggregated and descriptive data
- Tableau offers the Excel Reshaper Plug-in that can help: Excel Reshaper
1. Prepare Data File
Here is the original file for Fleetwood which lists the Patron Circulation Statistics for 2015 by Patron Code:

And here is the Tableau ready file:

2. Open Tableau and connect your excel file
In the Connect dialog box click on Excel:
Note the other file types you can connect to (Text file, Access or Statistical file)

Choose the file you would like to connect to from the Open dialog box:

Drag the worksheet you would like to connect to into the "Drag sheets here" area. If your spreadsheet only has one worksheet, Tableau will automatically use that sheet.
Tableau will attempt to sort out the data types in the sheet. You can adjust the data type by clicking on the blue data type markers above the column headers (here you would click on the Abc above "Patron Code" or the # above "Checkouts"