Mention what are the missing patterns that are generally observed?

The missing patterns that are generally observed are

Missing completely at random
Missing at random
Missing that depends on the missing value itself
Missing that depends on unobserved input variable

What is a good data model?

The criteria that define a good data model are:

It is intuitive.
Its data can be easily consumed.
The data changes in it are scalable.
It can evolve and support new business cases.

When Analyzing Data, What Are Some of the Statistical Methods Used?

There are quite a few answers you can give to this question, so be prepared to answer without much hesitation. Some of the examples you should give to your interviewer include the simplex algorithm, Markov process, and bayesian method.

Why do you think creativity is important for a data analyst? How have you used creative thinking in your work so far?

A data analyst is usually seen as a professional with a technical background and excellent math and statistical skills. However, even though creativity is not the first data analyst quality that comes to your mind, it’s still important in developing analytical plans and data visualizations, and even finding unorthodox solutions to data issues. That said, provide an answer with examples of your out-of-the-box way of thinking.

Example
“I can say creativity can make all the difference in a data analyst’s work. In my personal experience, it has helped me find intriguing ways to present analysis results to clients. Moreover, it has helped me devise new data checks that identify issues resulting in anomalous results during data analysis.”

Two buses running towards each other on the same track are moving at a speed of 40km/hr and are separated by 80km. A bird takes it flight from the bus A and flies towards bus B at a constant speed of 100km/hr. Once it reaches bus Y, it turns and starts flying back towards bus X. The bird keeps flying to and forth till both the buses collide. Find the distance traveled by the bird.

The solution to the above problem can be as follows:

The velocity of the two buses approaching towards each other = (40 + 40)km/hr
The time taken for the buses to collide = 80km/hr = 1 hour.
The total distance traveled by the bird = 100km/hr * 1 hr = 100 km.

Have you worked in an industry similar to ours?

This is a pretty straightforward question, aiming to assess if you have industry-specific skills and experience. Even if you don’t, make sure you’ve prepared an answer in advance where you explain how you can apply your background skills from a different field to the benefit of the company.

Example
“As a data analyst with financial background, I can say there are a few similarities between this industry and healthcare. I think the most prominent one is data security. Both industries utilize highly sensitive personal data that must be kept secure and confidential. This leads to 2 things: more restricted access to data, and, consequently, more time to complete its analysis. This has taught me to be more time efficient when it comes to passing through all the security. Moreover, I learned how important it is to clearly state the reasons behind requiring certain data for my analysis.”

Name the statistical methods that are highly beneficial for data analysts?

The statistical methods that are mostly used by data analysts are:

Bayesian method
Markov process
Simplex algorithm
Imputation
Spatial and cluster processes
Rank statistics, percentile, outliers detection
Mathematical optimization

What is Collaborative Filtering?

What is Collaborative Filtering?Collaborative filtering is a technique used by recommender systems by making automatic predictions or filtering about a user’s interests. This is achieved by collecting information from many users.

What is A/B Testing?

A/B testing is the statistical hypothesis testing for a randomized experiment with two variables A and B. Also known as the split testing, it is an analytical method that estimates population parameters based on sample statistics. This test compares two web pages by showing two variants A and B, to a similar number of visitors, and the variant which gives better conversion rate wins.

The goal of A/B Testing is to identify if there are any changes to the web page. For example, if you have a banner ad on which you have spent an ample amount of money. Then, you can find out the return of investment i.e. the click rate through the banner ad.

What are the important responsibilities of a data analyst?

This is the most commonly asked data analyst interview question. You must have a clear idea as to what your job entails.
A data analyst is required to perform the

following tasks:

Collect and interpret data from multiple sources and analyze results.
Filter and “clean” data gathered from multiple sources.
Offer support to every aspect of data analysis.
Analyze complex datasets and identify the hidden patterns in them.
Keep databases secured.