9 Data Visualisation Interview Questions And Sample Answers

Data visualisation is the graphical or visual representation of data and it enables organisations across industries to interpret trends, make forecasts and identify patterns. Data visualisation jobs require a specific skill set based on which the hiring manager may ask questions that evaluate whether you are right for the job. Knowing how to answer these questions can enable you to distinguish yourself as a preferred candidate during the interview process. In this article, we discuss nine common data visualisation interview questions, guide you on how to answer them and provide example answers.

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9 Common Data Visualisation Interview Questions And Sample Answers

Here are nine frequently asked data visualisation interview questions with sample answers:

1. How do you describe good data visualisation?

Through this question, your interviewer may want to understand how you combine your technical knowledge with your work experience. To answer this question, focus on the aspects of data visualisation that make it useful to the end-users and also talk about how you have utilised these aspects in your previous jobs to make recognisable visualisation for organisational data.

Example: "Theoretically, good data visualisation is one that appeals to the user. It also has to be accessible and useful. Simplification of data and showing only what is required are also aspects that make a good data visualisation. At my previous jobs as a developer, I noticed that good visualisation also involves scalability and a smaller amount of time to design."

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2. Can you represent more than three dimensions in one chart?

This is a technical question through which the interviewer may want to test your domain knowledge. They may want to understand how thorough you are with the working concepts of data visualisation. To answer this question, talk about how you can use colours or sizes to represent the fourth dimension. You can also give an example of where you have represented such elements in the past.

Example: "Usually, when we visualise data through an image, we represent it through the height, the width and the depth of the image. There have been many instances in my previous job where we had to use a fourth or even a fifth dimension of data. In such cases, I often suggested representing the fourth dimension as the size of the elements of the chart and the fifth dimension as the colour of the elements."

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3. Can you tell us what are the differences between Tableau and traditional BI tools?

Tableau is one of the most extensively used data visualisation tools. Many organisations may still use traditional business intelligence (BI) tools and may want to know whether you are adept at working on both types of tools. You can answer this question by highlighting the technical differences between the two types of software.

Example: "The last organisation I worked for used a traditional BI tool for several years. It was good at data manipulation but had limited visualisation capabilities. There were also hardware limitations and were based on complex technologies. When we switched to Tableau, we found it has a much wider range of visualisation options. It is also easier to use and more dynamic. Tableau can also be helpful for predictive analysis and it does not depend on any specific hardware."

4. Can you tell us about the various Tableau products and how you use them?

This question is also a way for the interviewer to determine your knowledge of the Tableau tool. To answer this question, you can talk about the different Tableau products and their uses. You may also add examples from your past jobs to elaborate on how you have used these different products.

Example: "Tableau has five products, Tableau Desktop, Tableau Server, Tableau Online, Tableau Reader and Tableau Public. At my last job, I extensively used Tableau Desktop to create data visualisation and Tableau Server to share the charts with other teams. Through Tableau Online, I published my dashboards and my clients viewed them on their respective Tableau Readers. As Tableau Public is a free version of the software with limited functionality, we incorporated the other products."

5. How do you use filters and content packs in Power BI?

Even though many organisations are switching to Tableau, some companies may still use Power BI. Your interviewer may want to know about your technical knowledge of Power BI through this question. You can answer this question by giving examples of Power BI filters and content packs that you may have used in any of your previous jobs.

Example: "Power BI has three types of filters, including drill through, page-level and report-level. In my role as a data visualisation specialist at Visual Inc., I extensively used drill-through filters to focus on customers and suppliers on the charts. When we shared our reports across teams, we also used page-level filters to filter charts on each page and report-level filters to filter charts across all pages. Content packs are a feature that allows the sharing of packaged reports, dashboards and datasets. We used content packs when we had to share reports using internal workspaces across teams."

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6. Tell us about the main hardware and software requirements for computer graphics.

Data visualisation involves working with advanced charts and graphs that may require high-level computer graphics. Your interviewer may want to know your understanding of the basics of computer graphics. They may also want to evaluate your awareness of technical specifications outside of the visualisation tools that you use. To answer, you can list the required computer components for graphics.

Example: "Apart from the basic computer components such as the motherboard, RAM and the hard drive, you also require a high-rendering graphics card for advanced visualisation. A monitor with a high resolution may provide clarity of colours in the charts. In my experience, sometimes we had to export some charts for presentations. A good colour printer can help see the data in a physical form for such scenarios. If you use Tableau, it can work on all operating systems."

7. In data visualisation, how do you do a 3D transformation and what are its benefits?

This might be one of the tricky data visualisation interview questions as through this, the interviewer may want to know about your depth of knowledge in the field. Companies that work on advanced data visualisation often produce a three-dimensional (3D) transformation of the data to understand the data comprehensively. You can answer this question by listing the steps and benefits of 3D visualisation.

Example: "The steps in the 3D transformation of data visualisation are modelling transformation, viewing transformation, projection transformation and workstation transformation. The primary benefit of 3D transformation is communication. It helps the user understand complex data thoroughly. Another benefit of 3D transformation is identifying design flaws. This is beneficial to the developers as they can change the visualisation techniques if the 3D transformation shows that the model requires improvement."

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8. Can you tell us about the challenges you encountered when working with big data?

Many organisations work with big data. Designing visualisation for such kinds of data may require working on extensive data processing and quality checking techniques. These processes often involve some challenges. Through this question, the interviewer may want to understand whether you have the requisite knowledge regarding all aspects of big data management. You can answer this question by expanding on big data's five characteristics, which are volume, veracity, value, velocity and variety. You may also include examples from your past jobs where you solved big data challenges.

Example: "As big data involves a large amount of information, it can sometimes get tough to manage it. It also gets generated rapidly and this may sometimes make it difficult to run proper quality checks. It has a lot of variety and it is often challenging to separate the correct data from the incorrect data. Sometimes, it can also be tedious to know which information from the datasets can provide value to the customer. At my previous job, my team used modern techniques such as compression, de-duplication and tiering to counter the challenges of big data."

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9. Why do you find a career in data visualisation interesting?

The interviewer may ask this question to evaluate your career goals and determine whether you are the right person for the open position. To answer this question, you may talk about your professional accomplishments and your ambitions. You can also focus on the achievements and vision of the company where you are interviewing. Present your answer with a genuine interest in the technical and business aspects of data visualisation.

Example: "I always had a knack for solving complex problems and presenting them through simpler methods. I have also had an interest in representing data in the form of charts and graphs even before the big data revolution. I have gained a lot of appreciation in my last jobs for the technology I used to process and present highly unintelligible data into information that everyone can process. It is my aim to continue to upskill in this area and contribute to the growth of your organisation's mission by consistently delivering easy-to-process information."

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