information with the use of color. The reference lines provide average sales values for each region and department. One could argue that the bar chart doesn’t communicate the details available in the text table, but in Figure 1-3 those details are provided via tooltips that pop out when you point your mouse at the mark of interest.
Figure 1-3: Tooltips provide details on demand.
Appropriate visual analytics improve decision making by highlighting the important outliers and making them easier to see. Interactive analytics make those details come to life by allowing your audience to explore areas of interest.
Turning Data into Information with Visual Analytics
Data that is overly summarized loses its ability to inform. When it’s too detailed, rapid interpretation of the data is compromised. Visual analytics bridges this gap by providing the right style of data visualization and detail for the situational need. The ideal analysis and reporting tool should possess the following attributes:
• Simplicity: Be easy for non-technical users to master.
• Connectivity: Seamlessly connect to a large variety of data sources.
• Visual competence: Provide appropriate graphics by default.
• Sharing: Facilitate sharing of insight.
• Scale: Handle large datasets.
Traditional BI reporting solutions aren’t adapted for the variety of data sources available today. Analysis and reporting can’t occur in these tools until the architecture is created within the proprietary product stack. Tableau Software was designed to address these needs.
Analysis as a Creative Process
Tableau’s design encourages interaction with data because the information consumer gets immediate feedback. Tableau’s CEO, Christian Chabot, talked about this in his keynote address at Tableau’s 2014 customer conference in Seattle.6 Chabot compared data analysis to artistic expression and explained that the way artists go about creating art (through trial, error, and refinement) is informing Tableau’s design.
• Encouraging experimentation
• Giving speedy feedback
• Providing an expressive environment
• Giving users control
The most impactful Tableau analyses are discovery stories. Sometimes discoveries translate into millions of dollars of improved profit for Tableau users. In Chapter 6, you’ll learn proven discovery techniques that will provide some examples for you to apply, refine, and develop into your own discovery methods.
Each new release of Tableau Desktop improves its reporting, analysis, and discovery capabilities. The next section provides a brief introduction into Tableau’s product line.
Tableau’s Desktop Tools
Tableau Desktop is the design tool for creating visual analytics and dashboards. There are two versions: Personal edition and Professional edition. Professional is more popular because it connects to a wider variety of data sources than Personal. If there isn’t a connector for the specific data you need to access, you can connect to it via the Open Database (ODBC) standard.
Tableau also provides a free consumption tool called Tableau Reader.
Tableau Desktop Personal Edition
Tableau Desktop Personal edition is the entry-level design tool that connects to data sources located in a file on your personal computer. It supports data connections to Excel, Access, text files (.csv), OData, Microsoft Windows Azure Marketplace DataMarket, and Tableau Data Extract (.tde) files. You can also import workbook files from other Tableau workbooks.
Professional Edition
Tableau Desktop Professional edition is similar to the Personal edition but offers a much wider range of data connections. In addition to the “In a file” options provided by the Personal edition, you have the ability to connect to a wide variety of database files. Desktop Professional connects to relational databases, columnar-analytic databases, data appliances, NoSQL data sources, web-service APIs, and other ODBC 3–compliant data sources. See Appendix B for a complete listing of connections for the Windows and Mac OS X editions.
Tableau File Types
You can save and share data using a variety of different file types in Tableau. The differences between each file type concerns the amount and type of information being stored in the file. Table 1-1 summarizes different Tableau file types.
When you save your work in Desktop, the default save method creates a workbook (.twb) file. If you need to share your work with people who don’t have a Tableau desktop license or don’t have access to the data source, you can save your work as a packaged workbook (.twbx) by using the Save As option when saving your file.
Table 1-1: Tableau File Types
Tableau Data Sources (.tds) are useful when you frequently connect to a particular data source or you have edited the metadata associated with that data source in some way (renaming or grouping fields, for example). Using saved data sources reduces the time required to connect to the data.
Tableau Data Extracts (.tde) leverage Tableau’s proprietary data engine. When you create an extract, your data is compressed. In versions prior to V8.2, if your data source is from a file (Excel, Access, text), Data Extracts add formula functions that don’t exist in those sources – including Count Distinct and Median. Beginning with V8.2, the Data Extract is no longer necessary to gain these functions because connections using the newer optimized connection create a local temporary extract automatically.
If you are publishing workbooks via Tableau Server, Data Extracts provide an effective way to separate the analytical load Tableau generates from your source database.
Tableau Packaged Data Source (.tdsx) files provide a means for publishing data extract files (.tde) or any filed-based data to Tableau Server. The Data Server can then be scheduled to refresh these files at regular intervals automatically.
Tableau Reader
Tableau Reader is a free version that allow users to consume Tableau Desktop Reports without the need for a paid license. To make files consumable by Tableau Reader, save your workbook as a Tableau Packaged Workbook (.twbx) file.
Tableau Online Help
I hope that while reading this book, you have Tableau Desktop running nearby and go to it often to work on examples, explore other options, and access Tableau Online Help (TOH). TOH is an excellent repository of information that is frequently updated by experienced practitioners. If something in this text isn’t making sense to you, try searching the TOH for another perspective on the topic.
Introducing the Tableau Desktop Workspace
This book is intended as a supplement (not a replacement) for Tableau’s online manual. If you are running Tableau Desktop while you are reading, you should try pressing the F1 key in Windows or Shift+Command+? on the Mac and take a look at the online manual. Go to the Tableau Help menu and select the Watch Training Videos option. This will take you to Tableau’s training and tutorials website. Watch the introductory video and review the numerous training videos that are sorted by topic. Most of them range from 3 to 20 minutes in length. Using the training videos in combination with this book will jumpstart your Tableau learning and deepen your understanding of more advanced skills.
In the remainder of this chapter, you learn the basics of Tableau’s workflow and user interface.
New Workspace Design
Tableau