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# Learn From My Mistakes

So you read or heard about The Data School application process. You got interested, joined Tableau, got inspired and have your data ready. Now it’s time to create your viz. Before you do that, you might learn a lesson or two by reading about my application experience.

## My Original Viz

The first time I heard or read about Tableau was when I saw The Data School’s ad in one job searching site. I immediately searched for a basic tutorial video and watched it. After gathering my data, I created my first viz:

It looked very cool to me so I decided to submit it for my application. However, I learned that it is a very good example of visualisation no-no’s after getting these feedback:
1. Don’t reuse the same colour for two different charts because it’s creating confusion.
2. The image is a nice touch but it is taking up quite a lot of space.
3. Sort the Record bar chart by win percentage in order to determine which team he is dominating.
4. Use game averages instead of total for the Statistics bar chart so that the smaller stats won’t look insignificant.

Aside from that, here are other tips I received to make my viz more appealing:

1. Provide an eye-catching title to the dashboard.
2. Create an initial introduction since not everyone may be familiar with the topic of my viz.
3. Focus on a story to tell.

## The Updated Viz

I modified my viz based on the feedback and this is the result:

## Further Improvement by Using Parameters and Calculations

Looking back on my second viz, I realized there’s a very basic approach in Tableau that I could have used to make the viz better and less crowded. Notice that I have three similar graphs:

They can be combined in one graph using parameters and calculation. Let me walk you through on how to do this using my data:

1. Determine the measure values involved. In my case, I want to combine BLK (Blocks), PTS (Points) and REB (Rebounds).
2. Create a parameter. You can do this by clicking on the triangle button in the Data tab and selecting Create Parameter. Similarly, the option can be accessed by right-clicking on the empty space below the Tables.
3. Give the parameter a proper name. I used Integer as Data type to associate an integer to a measure value. After that, choose List for the Allowable values and in List of values, assign an integer to the display name you want for your measure values.
4. Create a calculated field for the parameter. Right-click on the parameter, hit Create and then Calculated Field.
5. Give the calculated field a proper name. I used the CASE function to associate the integers set in the parameter to the measure values.
6. Use the calculated field to create the graph. Afterwards, Show the parameter and use it to select a measure value.

## Second Stage Preparation

I hope the tips in this blog can help you pass the first stage of The Data School application process. If you do make it to the second round, prepare by improving your presentation skills.

##### Author: JB Reyes

JB hails from the Philippines where he was an anti-malware engineer for 5 years. After moving to Australia in 2017, he worked his way up in a school supply company starting with a role as a despatcher and then taking on roles in IT support and bookkeeping. His passion for data is so deep that he can spend hours exploring and analysing data without tiring or getting bored. When JB is not all over data, he spends his time playing basketball, Pokémon cards with his daughter and building robot plastic models. If there is one dish that he would have to eat for the rest of his life, it would be Lechon, a Filipino delicacy (roasted pig) that reminds him of home.