9 Questions and Answers for a Data Science Job Interview in 2022
Data science is one of the tech fields that is growing the fastest. It uses many different ways to get useful information from both structured and unstructured data. Employers need people with experience and skills in data science, which includes statistics, data analysis, machine learning, and other similar fields. This article gives you examples of how to answer data science interview questions so you can prepare for your interview and get hired as a data scientist. Answers for a Data Science Job Interview
What does it mean to study data?
Data science is a field that uses data to organize, analyze, and find insights that can help people make better choices. Companies and industries collect a lot of data, and they use the results in different ways to figure out how to improve their business processes. For instance, businesses can get feedback from customers in many different ways and learn a lot about what their customers want and need. Based on this information, they might change how they market or make a new product.
Because data science is such a broad field, people who want to work in it need strong technical skills in math or computer science as well as soft skills like the ability to work well under pressure and good communication.
Common data science interview questions
Here are the nine most common data science interview questions:
- Why do you want to work at this company as a data scientist?
- How have your previous jobs prepared you to be a data scientist?
- What do you do when things go wrong at work?
- What tools and tech do you plan to use as a data scientist?
- What is selection bias, and why should you try to avoid it?
- How do you put a lot of information together?
- Is it always a good thing to know a lot?
- What is root cause analysis?
- How do you usually find outliers in a set of data?
1. Why do you want to work at this company as a data scientist?
This question gives you the chance to talk about what you like about data science, the job description, and the company as a whole. You can talk about how interested you are in technology, analytics, or using big data to help the company reach its goals. You can also say that you are especially interested in how that company gathers and looks at a lot of data.
Example: “I have a degree in computer science, and I love to solve problems by processing and analyzing data. So, I want to work for a company that is forward-thinking and data-driven, and that has a long history of using data to make its products better. I’m excited to find a job where I can reach my career goals and do well at work I’m passionate about.
2.How have your past jobs helped you get ready for a job as a data scientist?
Because this job requires a wide range of skills, you may need to show that you have relevant experience in both technical skills and talking to other people. The STAR interview response method is the best way to explain how your past experiences have prepared you for a job in data science. This means talking about a situation, what your job was in that situation, what steps you took to finish the job, and what the results of those steps were.
“At my last job, I worked for a tech company where I got customer feedback on their apps from a variety of platforms and sent monthly reports to upper management about what I had found. My main job was to find problems that most customers had in common, no matter what device they used to access the company’s apps.
I made an algorithm that took all of the customer feedback and put it into groups based on the keywords that customers used. This was the most efficient way to get the data. I was able to make collecting and analyzing these huge amounts of data more efficient, which made it easier to group the data and draw conclusions from it.
3.What do you do when problems come up at work?
This question gives you a chance to show how you solve problems and think critically on the job and in a team. Data scientists often have to solve hard problems, so your answer should show that you can find ways around problems and keep your mind on the task at hand. Pick a project or time when you used your skills to solve a problem to show the company what you could do for them.
Example: “I think the best way to solve a problem on a team like this is to have an open conversation with my coworkers. At my last job, my team had to figure out what a new set of data meant for the marketing department. We had to look through a lot of information, but it wasn’t clear what each person on the team was supposed to do. I called a meeting with everyone on the team and our managers to make sure everyone knew what their jobs were. So, when we were given new projects, we came up with a good way to divide the work.
4. As a data scientist, what gadgets and tools do you plan to use?
This question is meant to find out what programming languages and tools you can use. You can talk about how you use the tools you use most often to get things done quickly and well in your answer. Think about talking about a recent project you finished and how you solved a problem using a single language or set of tools.
“I just finished a big research project that helped me figure out what kind of product design customers would like best. I knew how to use SQL and Tableau, but I didn’t know how to use FUSE and Python. For this project, it was up to me to collect and organize a lot of data using the FUSE and Tableau platforms for data mining and making connections. Then, when I got new information, I used Python to make algorithms and SQL to update my database. I learned more about SQL and Tableau and how to use them after working on the project for three months. I also learned Python and became good at it, but I want to use it more.
5. What is selection bias, and why is it important to avoid it?
In data science interviews, questions about selection bias come up a lot because they give you a chance to show that you can pick completely random sets of data to make sure your insights are correct. You can show what you know about the topic and what you think about it by explaining what selection bias is, why it’s important, and how to avoid it.
“Selection bias is when you can’t pick samples of data at random. I avoid selection bias in all of my projects because data science depends on the randomness of the samples when comparing them to the whole database to make sure the results are right.
As my final project for my undergrad program, I had to rank all of the professional basketball players in the state based on how well I thought they would do the next season. I used boosting, weighting, and resampling to make sure I didn’t unconsciously favor the players I liked the most. This process made sure that my data were the most accurate representation of what I was reporting on.”
6How do you put a lot of information in order?
As a data scientist, you will often need to combine large amounts of data from different platforms and organize them in a way that makes it easy to analyze them further. This question is important because it shows how well you can organize a lot of information. Your answer should show that you know how to organize data and what tools are needed to do so. Think about talking about a time when you organized a lot of data, what tools you used, and what the results were.
Example: “At my last job, I organized big sets of data by first figuring out how relevant they were and then getting rid of the data sets that didn’t fit the logic I had set. I recently had to sort a list of everyone with diabetes in a state by age, gender, and other things. I was able to clean up the data by automating the cleaning process with Paxata. Using Paxata and figuring out how important each data point is helps me find the most important data and get the best insights.
7. Is having a lot of information always better?
This is a common question asked during interviews for jobs in data science. Its purpose is to find out what the applicant thinks about data in general. You can give a balanced answer by saying that the best amount of information often depends on the situation. Use the STAR method by giving examples from your work life to show what you know.
“Most of the time, you need to do a cost-benefit analysis to figure out if having a lot of data is good or not. When you have a lot of data, you need more computing power and more memory, among other things. So, it may be more important to find out if the data is fair and useful than how much there is of it.
I used to work for a company that did local election polling. My job was to sort the information based on how old the people who answered the questions were and what they did for a living. I found that a lot of people were similar in important ways after looking at the data. I came to the conclusion that, even though we got information from a lot of people, we would have gotten the same results from a smaller group.
8.What does it mean to find the root cause?
A big part of a data scientist’s job is to use data to find problems and figure out how to solve them. Root cause analysis is a very important part of the process that tries to find the first problem to figure out the order of problems that led to the problem. Your answer should show that you know how to do a root cause analysis and have done them before. This question is your chance to show the company you want to work for that you’re qualified for this data science job.
Root cause analysis is a way to find out what went wrong that led to a problem in the first place. When I worked for a company that made things, I used root cause analysis. I had to use it to figure out why things weren’t working right, like when a part broke or a sensor’s value was wrong, or when the control logic or the environment changed. I was able to make an algorithm that figured out what would happen next based on how things were going right now. This made the process of making things much less likely to go wrong.
9.How do you usually look for “outliers” in a group of numbers?
Successful data scientists need to be able to use their theoretical knowledge to come up with results and conclusions that work in the real world. This question is your chance to show how you use your analytical skills to find outliers and other data effects in different situations. To give a good answer, talk about a specific work experience that best shows what you know.
“Most of the time, I use practical methods and look at the raw data to figure out what the general trends are. Then I can figure out which model will help me find outliers. I recently made a list of all the professional basketball players in the state based on how many points they scored on average per game. I was able to find outliers by making histograms for each player and using statistical tools like quartiles and inner and outer fences to make sure my results were correct.
