What is Tableau?

By | May 16, 2020
What is Tableau

The literal meaning of the word ‘Tableau’ is ‘picture’ or figure that represents a story or scene. That’s precisely what the software tool means, too, as we will explore in this article. Apart from understanding what a tableau is, we will also explore the different flavors it comes in, why learning Tableau is essential both for programmers and non-programmers, and then dive into a small example (using the free version of the software) to show how easy Tableau is.

Tableau is the name of an American company that has developed a business intelligence (BI) tool (of the same name). It is one of the best tools in the data industry today.

Vamware

What is a business intelligence tool?

Business intelligence tools provide methods and strategies to collate past, current, and future(predictive) data and generate useful business insights for data analysis and making essential business decisions. BI tools can easily handle a large amount of data from various data sources. The data can be structured or unstructured. Using such tools saves a reasonable amount of time and resources, making them the need of the hour for today’s data-driven world.

Tableau does all of the above! Here are some uses of Tableau –

  1. Drag and Drop Functionality
  2. Import Data From Multiple Resources
  3. Present Data in Visual Form
  4. Custom Report Generation

Uses of Tableu

Why Tableau? Is it worth learning Tableau?

Do you remember working on Microsoft Excel? Yes, we all have used excel at some point – for creating an invoice for reading table data, filtering, finding sum, etc.… Excel works perfectly for a small amount of structured data, however, for vast volumes of data being generated every day, a more robust tool like Tableau becomes the natural choice (You will see that later in the article).

What is Tableau?

Of course, it is a BI tool. Still, more specifically, it is a data visualization tool that can generate charts, reports, and other visualizations – basically, transform a lot of data into easy-to-read and comprehend format without you having to know any technical skills or programming knowledge. It is an ideal tool for Business analysts.

Anything showed as a visual just register in our minds better than text. Further, Tableau can calculate all the fields like average, median, mean, standard deviation, variance, etc for you. For more complex charts, you may need some knowledge on writing simple queries, for example sorting based on multiple conditions, or grouping data based on different factors. Still, for the most part, you will not write anything. Just drag and drop!

Apart from the fact that Tableau is flexible, secure, fast and powerful, here are the following features that give it the edge over any other BI tool –

  • Highly interactive solution with real-time data analysis and data blending
  • No coding or technical skills required
  • Easy integration with R and Python
  • Can combine data from multiple data sources, able to handle large data sets
  • Easy to learn and fun to use
  • Mobile support
  • Interactive dashboard
  • Enables faster project completion
  • Each version comes with new capabilities based on user suggestions
  • Great community support and documentation

As per Gartner ratings, Tableau has been recognized as one of the leaders in BI and analytics for the last six years.

BI and analytics

Aren’t you convinced enough to explore Tableau further? Well, in case you are not, what we have also in this article will undoubtedly convince you to learn and use Tableau! You can practice Tableau for your learning as well as your enterprise’s needs.

Tableau Product Suite

Here is what you get in the Tableau product suite –

  • Tableau Desktop
  • Tableau Public
  • Tableau Online
  • Tableau Server
  • Tableau Reader
  • Tableau Prep

1. Tableau Desktop

Tableau Desktop allows you to conveniently view the story in your data through loads of options. You can drag and drop rows and columns to see different combinations of data and work on it to arrive at new trends, outliers – visually. You have plethora of options in the dashboard – like connecting to a data source from the list of available sources (can be excel sheet, MySQL, SQL Server, Oracle, significant data sources, data warehouses, cloud databases etc…), mix and match, drag and drop from any of the sources into a single view. You can perform various actions like creating maps, finding out the sum, median, or use filters – basically, play with data in any which way you want to. You can switch between different charts (for example, a Treemap to the histogram, etc…) and find the view that is most useful for the current set of data. The software also finds trends and forecasts – all you have to do is click on the necessary options! Multiple people can access the interactive dashboards through the Tableau Server or Tableau online tools. There are two versions –

  • Tableau desktop personal – limited access, work can be shared only through Tableau Public. These are own workbooks created in private mode.
  • Tableau desktop professional – full access to all data sources and work can be published on Tableau server, ideal for users in the same organization who want their work to be presented at various levels.

2. Tableau Server

With Tableau Server, you can share your workbooks, and multiple users can access it through desktop or mobile anywhere, any time. All this, in a secure environment. This helps businesses create insights and answer in-depth questions on the go, making project execution faster and easier. You can load different sources and extract data from these sources or use live data for your analysis. Tableau server ensures you are using the right data for your review. It has options to inform others if a particular data set/field is obsolete for use through a simple message. By creating colorful visualizations, you can focus on the areas that need improvements for your business to grow further. Whether you drag and drop fields to get your answer or type your query in natural language, you will instantly get your answer in a visual form. The server enables data management like adding/removing data sources, permissions, views, subscriptions, and thus enhances manageability, security, and scalability.

3. Tableau online

Tableau Online is a SaaS that you can use anywhere, without the need for hardware installation. You can explore, modify, visualize, and create insights through the browser, tablet, or even mobile phone. You can access different data sources and connect to them on-premises or through the cloud. You can add as many users as you want to access the workbooks that you create and work on the data together. This is a compelling use of technology that enables you to perform trusted and quick analysis as a team. Like I mentioned before, you can also create your work on Tableau Desktop and then share and collaborate with others through Tableau online for them to access your work and ask their questions with the data for different perspectives.

4. Tableau Reader

This is a read-only mode where a user with whom a workbook has been shared can view the visualizations and apply some basic filters without modifying the results. Books can be shared through Tableau Desktop or Tableau Public.

5. Tableau Prep

This is a powerful tool that helps you view all your data in a single window and helps you clean and prepare data for visualization. You can combine, reshape, reorganize and clean data from multiple sources visually – drag and drop the parameters that you need to prep(are) your data – aggregate, union, join, etc.… You can also use calculations, see the results of joins and other query parameters to represent data in different ways. Outliers and data inconsistencies can be fixed within minutes with this tool. You can view the changes as you perform them. If you think you made a mistake, you can go back to any previous versions in a click. You can also keep track of the workflows, schedule them, and receive alerts if something fails. The flows are integrated so that you can monitor and share the data across your organization through Desktop or Online.

Tableau Pre 1

Tableau Pre 02

6. Tableau Public

This is the version we will use for our learning, and it has been created for the same purpose. It is nothing but the public release of Tableau Desktop. The workbooks are not secure and cannot be stored locally. They are stored in Tableau’s public cloud. That means even you can access the books shared by others. Most learners and first-time users use Tableau Public to get a hands-on of Tableau.

Okay, enough for the theory,

  • Let’s get to a little practicing now –
  • Download Tableau Public here and follow the on-screen instructions to install it.
  • Once you have installed and opened Tableau, you should connect to a data source. As we know, the data sources can be anything – excel, CVS, SQL server, Hadoop, etc.…
  • I have created my dataset (with limited data) using excel for showing an example. You can explore the existing sample datasets, too if you wish to.

Consider this set of data,

1

Out of the total rows, few are shown here. The data shows the names of students who have joined on a particular date, their location/birthplace, the average grades, average marks, and other information.

This data will be seen in the 1st tab of the Tableau tool. Once you load the data, you can move to sheet1. This is where all the magic happens.

1

In the above example, I have generated a stacked bar that tells about the average marks by Male (m) vs. Female (f) students. The parameters in green are measures (numbers like average, sum, height, weight, etc..), and those in blue are called dimensions (location, name, grade, date, etc…). For this chart, we have to pull the gender dimension to the Marks tab and average marks measure on to rows (change the calculation from SUM to AVG) –

3

We can drag and drop any size or measure depending on the results that we need and switch to any other type of chart as required. The right bottom shows how many steps or dimensions or measures we need for every kind of table to be generated. The above graph displays continuous value; however, we can also show discrete value –

Discrete Value

Let us say; we want to know the grades of each student based on their average marks. All you do is the select average of the average marks row, drag and drop category and name columns, select the chart of your choice and bingo!

4

5

You can see that the data is neatly grouped based on the grade. The left diagram shows a histogram while the right one represents Treemap.

If you have your data to work with for practice, you can keep adding more columns to increase the complexity. The more data you have, the more fun you can have playing around with it. For example, if I add a country column in my sheet, I can group students based on the country and get their median or average marks. Same way, I can add a column for primary subjects and then analyze data on which topics are the most scoring for the students and so on.

Let us say we want to know who all have scored average marks above 80 and in which subjects. I can easily create a filter as –

6

Once I drag the screen, I am presented with something like this –

8

Few things to notice in this –

  • Data for all the students is shown; the ones who have average marks of less than 80 are grouped under false. If you now go back to the data source tab, you will see this calculated field (avg_marks_above_80) added as a column with values true or false.
  • The color-coding indicates the location they are from. For example, pink is for Germany, Orange for India, and so on. Tableau puts default colors, but we can change it – check out the dimension birthplace on the Marks card.
  • If I want to see only the records that have the value false, I can edit the filter and untick true,

9

Same way, if I want to know what country do the students who have scored above 80 in each subject belong to, I can drag and drop those columns –

10

11

You can drag the country in the Marks card and apply colors –

12

Based on the country/region name, Tableau automatically calculates longitude and latitude and displays the same in two different formats.

We can represent the same using other charts like stacked bars or side-by-side bars. Let us get this information in a side-by-side bar –

  • Drag the average marks and significant subject to the rows.
  • We have already added a calculated field named avg_marks_above_80, and we are categorizing the information based on birthplace, so drag both as columns.
  • Edit avg_marks_above_80 filter to display only True values.

You will get a chart like this –

Chart1

But all the values look almost the same. This is because the variations are small in our data. We can start the index from 80 instead of 0, and then we can appreciate the differences more. Double click on the axis (average marks) and a window will appear:

Double Click

Change the range from automatic to fixed and specify the range. Move to the next tab (Tick Marks) –

Chart 2

Again, change the values of Tick origin and interval as desired. Now, we see the variations more clearly –

Chart 4

Try creating another calculated field with average_above_90 and see if you get the following –

Chart 5

Note that these examples have been created for learning purposes so that we can understand more features of Tableau. You can play around as much as you want by moving around the columns and rows up and down and see how the charts change.

Let us learn a little about line charts –

Tableau will show you what parameters you need to generate a line chart –

Chart 6

Let’s say you want to calculate the average marks obtained by the class based on the year of joining and the primary subject. Sounds a lot.

Tableau will do it all for you – you have to drag and drop all the rows and columns you need.

Chart 7

Take the blue line (English), for example.

  • As per our data, there are no students who took English as a significant in 1983 and 1986.
  • In 1984, the average marks of those who had English as a significant were 84.9, as pointed in the chart ((93.6 + 76.2)/2). If you hover your mouse on the point, you will get the details –

Chart 8

The same holds for other subjects too.

All of this is just a representation of data. The real power of Tableau comes with analysis using trend lines and forecasts. The tool uses AI to show trends, discover patterns, and predict the future. To predict or forecast, we need data for a more extended period.

Let’s try to get some insights from this data –

Click on Analysis, Trend lines and then Show trends –

Chart 9

Tableau will show something like this –

Chart 20

We can infer that while English and Science show a general upward trend, Maths shows a downward trend.

But this data, as we said, is not enough to generate the forecast. I have added some more data of students with different years of joining. Let us get the same line chart for the new dataset –

Chart 21

The data we have now is for ten years instead of 3 years. Let us draw the trend line now –

Chart 22

As we see, with more data, we have better trends compared to previous trends. We see a downward trend for English, whereas Math is almost stable (no steep trend). If you click on to describe the trend, you can get all the mathematical values that are needed for in-depth analysis –

Deep Analysis

Let us now generate a forecast for the next three years –

Chart 23

If you don’t like the crisscrossing of lines, add major subjects as a row, and you will get individual lines.

Chart 24

Just for fun, switch from line chart to area chart to see the same results –

Chart 25

We can see the description of the forecast –

Chart 26

Graph 27

Notice that for Maths, the prediction quality is still OK, but for others, it is not so. This could be because the data is insufficient or not of good quality. The forecast also shows a negative trend for English. The critical point here is how detailed the analysis is, without us putting any effort. Every calculation was done by Tableau within minutes. We could swap rows and columns, add/remove columns and play around with data to see different results.

Summary

This article is not exhaustive and does not cover every feature and option of Tableau. Tableau 10 Business Intelligence Cookbook or Tableau for dummies are some excellent books to start your journey. Along with that, you can watch some excellent tutorials on YouTube that teach loads of features of Tableau. For the most part, though, you wouldn’t need a detailed tutorial – download the free version and explore it yourself. The tableau documentation is quite comprehensive and crisp.

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