90+ Junior Data Analyst Interview Questions and Answers

Data mining involves discovering patterns and relationships in large datasets, while data analysis focuses on interpreting and drawing insights from data.

• Data mining is the process of extracting useful information from large datasets.

• Data analysis involves examining and interpreting data to draw conclusions and make informed decisions.

• Data mining uses techniques like clustering, classification, and association to discover patterns and relationships.

• Data analysis involves tech...read more

Adverse event is any undesirable medical occurrence while adverse reaction is a specific type of adverse event caused by a medication.

• Adverse event can be caused by any medical intervention or procedure while adverse reaction is specifically caused by a medication.

• Adverse event can be expected or unexpected while adverse reaction is always unexpected.

• Example of adverse event: a patient develops a fever after surgery. Example of adverse reaction: a patient develops a rash afte...read more

Data analysis involves several steps including data collection, data cleaning, data exploration, data modeling, and data visualization.

• Data collection: Gathering relevant data from various sources.

• Data cleaning: Removing any errors, inconsistencies, or missing values from the data.

• Data exploration: Analyzing the data to understand its characteristics and identify patterns or trends.

• Data modeling: Applying statistical or machine learning techniques to build models and make pre...read more

Handled cases include data cleaning, analysis, visualization and reporting for various industries.

• Data cleaning and analysis for a retail company to identify sales trends

• Visualization of customer behavior for a telecommunications company

• Reporting on website traffic for an e-commerce business

• Data analysis for a healthcare provider to improve patient outcomes

• Cleaning and analyzing survey data for a non-profit organization

C is a procedural programming language while C++ is an object-oriented programming language.

• C++ is an extension of C with added features like classes, inheritance, and polymorphism.

• C++ is used for developing software applications, games, and operating systems.

• Website testing is the process of checking the functionality, usability, and performance of a website.

• It involves testing the website's links, forms, navigation, and compatibility with different devices and browsers.

• Webs...read more

PowerBI and Tableau are both popular data visualization tools, but they have some key differences in terms of features and functionality.

• PowerBI is a Microsoft product, while Tableau is developed by Tableau Software.

• PowerBI is more user-friendly and integrates well with other Microsoft products, while Tableau offers more advanced visualization capabilities.

• Tableau has a feature called Calculated Field which allows users to create new fields based on existing data, while Power...read more

Null values in an Excel sheet can be found by using filters or functions like ISBLANK or COUNTBLANK.

• Use filters to easily identify blank cells in the Excel sheet

• Use functions like ISBLANK or COUNTBLANK to check for null values in specific cells

• Look for cells with no data or missing values, which indicate null values

VLOOKUP can be used to find specific information in a table by matching a key value.

• Use VLOOKUP to find a student's grade based on their student ID in a table of student data

• VLOOKUP can be used to retrieve a customer's contact information based on their customer ID

• It can also be used to look up product prices based on product codes in a pricing table

I am familiar with basic SQL commands such as SELECT, INSERT, UPDATE, DELETE, JOIN, and GROUP BY.

• SELECT: Retrieve data from a database table

• INSERT: Add new records to a table

• UPDATE: Modify existing records in a table

• DELETE: Remove records from a table

• JOIN: Combine rows from two or more tables based on a related column

• GROUP BY: Group rows that have the same values into summary rows

Credit note is issued to reduce the amount payable by a customer, while debit note is issued to increase the amount payable by a customer.

• Credit note is issued when a customer has been overcharged or returned goods, resulting in a reduction of the amount owed.

• Debit note is issued when a customer has been undercharged or additional goods/services have been provided, resulting in an increase of the amount owed.

• Credit note decreases the accounts receivable balance, while debit n...read more

Congenital anomaly refers to a physical or structural abnormality present at birth.

• Seriousness criteria of cases depend on the type and severity of the anomaly.

• Some congenital anomalies may be minor and have little impact on health, while others can be life-threatening.

• Examples of congenital anomalies include heart defects, cleft lip and palate, and neural tube defects.

• Congenital anomalies can be caused by genetic factors, environmental factors, or a combination of both.

• Early...read more

List is mutable, ordered collection of items while tuple is immutable, ordered collection of items in Python.

• List is defined using square brackets [] while tuple is defined using parentheses ().

• Elements in a list can be changed or modified while elements in a tuple cannot be changed.

• Lists are typically used for collections of similar items while tuples are used for fixed collections of items.

• Example: list_example = [1, 2, 3] and tuple_example = (4, 5, 6)

Tuple is immutable, list is mutable in Python.

• Tuple elements cannot be changed once assigned, while list elements can be modified.

• Tuple uses parentheses () and list uses square brackets [] for declaration.

• Example: tuple_example = (1, 2, 3) vs list_example = [1, 2, 3]

Solicited report is a report requested by an authority while spontaneous report is a voluntary report by an individual.

• Solicited report is requested by an authority or organization.

• Spontaneous report is voluntary and not requested.

• Solicited report is usually for a specific purpose or event.

• Spontaneous report is usually for unexpected events or adverse reactions.

• Examples of solicited reports include clinical trial reports and regulatory reports.

• Examples of spontaneous reports ...read more

Data cleansing is the process of identifying and correcting or removing errors, inconsistencies, and inaccuracies in datasets.

• Data cleansing involves identifying and handling missing values in datasets.

• It also includes removing duplicate records or entries.

• Data cleansing may involve correcting spelling mistakes or formatting issues in data.

• It helps improve data quality and reliability for analysis and decision-making.

• Example: Removing rows with missing values, standardizing d...read more

Passion for uncovering insights from data and making data-driven decisions.

• Fascination with numbers and patterns

• Desire to solve complex problems

• Interest in using data to drive business decisions

• Ability to communicate findings effectively

There are four phases of clinical research: Phase 1, Phase 2, Phase 3, and Phase 4.

• Phase 1: Focuses on safety and dosage in a small group of healthy volunteers.

• Phase 2: Expands to a larger group to see if the treatment is effective.

• Phase 3: Compares the new treatment to standard treatments in a larger group.

• Phase 4: Post-marketing studies to monitor the treatment's long-term effects.

I know Python, SQL, and R.

• Proficient in Python for data analysis and visualization

• Experience with SQL for data querying and manipulation

• Familiarity with R for statistical analysis and modeling

A pivot table is a data summarization tool used to condense and aggregate large datasets.

• Pivot tables allow users to quickly analyze and manipulate large amounts of data.

• They can be used to group data by categories and display summarized information.

• Users can easily change the layout of the table to view data from different perspectives.

• Pivot tables are commonly used in spreadsheet programs like Microsoft Excel and Google Sheets.

• For example, a sales team could use a pivot tab...read more

Pharmacovigilance is the science and activities related to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems.

• Pharmacovigilance involves monitoring and evaluating the safety of pharmaceutical products.

• Adverse events are any undesirable experience associated with the use of a medical product.

• Examples of adverse events include side effects, allergic reactions, and medication errors.

• Pharmacovigilance aims to improve pat...read more

SUSAR stands for Suspected Unexpected Serious Adverse Reaction. Regulatory authorities include FDA, EMA, MHRA, etc.

• SUSAR refers to adverse reactions that are unexpected, serious, and suspected to be caused by a drug or medical product

• Regulatory authorities such as FDA (Food and Drug Administration), EMA (European Medicines Agency), MHRA (Medicines and Healthcare products Regulatory Agency) oversee reporting and monitoring of SUSARs

• Reporting SUSARs is crucial for ensuring the ...read more

Cross join combines every row from the first table with every row from the second table, while cross apply applies a table-valued function to each row of the first table.

• Cross join results in a Cartesian product of the two tables.

• Cross apply is used to invoke a table-valued function for each row of the first table.

• Cross join does not require a specific condition to join the tables, while cross apply does.

PowerBI Report is a collection of visualizations and data organized in a single page, while Dashboard is a single-page display of key metrics and KPIs.

• PowerBI Report contains multiple pages with different visualizations and data sets.

• Dashboards are a single-page display of key metrics and KPIs for quick insights.

• Reports are more detailed and allow for in-depth analysis, while Dashboards provide a high-level overview.

• Reports are typically used for detailed analysis and sharing...read more

Candidate key is a unique key that can uniquely identify each record in a table, while a compound key is a key that consists of multiple columns to uniquely identify each record.

• Candidate key is a single column key, while compound key is a combination of multiple columns.

• Candidate key can be a primary key, while compound key cannot be a primary key if it includes non-unique columns.

• Example: In a table of students, student ID can be a candidate key, while a compound key of stu...read more

The available data types in SQL include numeric, character, date/time, and boolean types.

• Numeric data types include integer, decimal, and floating-point types.

• Character data types include char, varchar, and text types.

• Date/time data types include date, time, datetime, and timestamp types.

• Boolean data type represents true or false values.

Joins are used to combine rows from two or more tables based on related columns.

• INNER JOIN: Returns records that have matching values in both tables.

• LEFT JOIN: Returns all records from the left table and the matched records from the right table.

• RIGHT JOIN: Returns all records from the right table and the matched records from the left table.

• FULL JOIN: Returns all records when there is a match in either left or right table.

• CROSS JOIN: Returns the Cartesian product of the two ta...read more

Convert decimal number to binary representation using division and remainder method.

• Start by dividing the decimal number by 2 and noting down the remainder.

• Continue dividing the quotient by 2 until the quotient is 0.

• The remainders obtained in reverse order will give the binary representation.

Stored procedure in SQL is a precompiled collection of SQL statements that can be executed by calling the procedure name.

• Stored procedures help improve performance by reducing network traffic and improving security.

• They can be used to encapsulate complex SQL logic for reuse.

• Parameters can be passed to stored procedures for dynamic execution.

• Stored procedures can also be used for error handling and transaction management.

Use the unique() function to find unique values in the dataset.

• Use the unique() function in Python with libraries like pandas or numpy.

• For example, df['column_name'].unique() will return an array of unique values in that column.

Natural Language Processing (NLP) is a field of AI that focuses on the interaction between computers and human language.

• NLP involves the ability of computers to understand, interpret, and generate human language.

• It encompasses tasks like text classification, sentiment analysis, machine translation, and speech recognition.

• NLP techniques include tokenization, part-of-speech tagging, named entity recognition, and syntactic parsing.

• Examples of NLP applications include virtual ass...read more

Provide clear instructions and support to partners for submitting assessments.

• Create a step-by-step guide on how to submit assessments

• Offer training sessions or webinars to demonstrate the submission process

• Provide a dedicated support team or help desk for partners to reach out to with any questions or issues

• Regularly communicate deadlines and reminders for assessment submissions

Reports can be categorized into operational, tactical, and strategic reports.

• Operational reports provide day-to-day information on business activities.

• Tactical reports provide information on short-term goals and objectives.

• Strategic reports provide information on long-term goals and objectives.

• Other types of reports include financial reports, performance reports, progress reports, and incident reports.

• Examples of reports include sales reports, inventory reports, budget report...read more

ICH-GCP guidelines are international standards for designing, conducting, recording, and reporting clinical trials.

• ICH-GCP stands for International Conference on Harmonisation - Good Clinical Practice.

• These guidelines provide a unified standard for the European Union, Japan, and the United States.

• They ensure the protection of the rights, safety, and well-being of trial subjects.

• ICH-GCP guidelines cover aspects such as trial design, conduct, monitoring, auditing, and reporting...read more

vlookup is a function in Excel used to search for a specific value in a table and return a corresponding value from another column.

• Syntax: VLOOKUP(lookup_value, table_array, col_index_num, [range_lookup])

• lookup_value is the value to search for in the first column of the table

• table_array is the range of cells that contains the table

• col_index_num is the column number in the table from which to return a value

• range_lookup is an optional argument that specifies whether to find an ...read more

Index and match are used in Excel to look up values in a table based on specific criteria.

• Index and match are used together to perform a vertical lookup in Excel.

• Index returns the value of a cell in a table based on the row and column numbers provided.

• Match is used to find the position of a value in a range of cells.

• Index and match are often used instead of VLOOKUP when dealing with large datasets or when the lookup value is not in the first column of the table.

Yes, I enjoy working with data as it allows me to uncover insights and make informed decisions.

• I find analyzing data to be intellectually stimulating

• I enjoy discovering patterns and trends within datasets

• Working with data helps me make data-driven decisions in my work

• I appreciate the challenge of cleaning and organizing data for analysis

Medra coding is a standardized medical terminology used for reporting adverse events and drug reactions.

• Medra stands for Medical Dictionary for Regulatory Activities.

• It is used by pharmaceutical companies, regulatory agencies, and healthcare professionals.

• It helps in identifying and analyzing adverse events and drug reactions in clinical trials and post-marketing surveillance.

• Medra codes are hierarchical and can be expanded to provide more specific details.

• Example: Medra code...read more

Pharmacovigilance involves several phases including signal detection, data collection, data assessment, risk management, and communication.

• Signal detection: Identifying potential safety issues through various sources such as clinical trials, spontaneous reports, and literature reviews.

• Data collection: Gathering information on adverse drug reactions (ADRs) from healthcare professionals, patients, and regulatory authorities.

• Data assessment: Analyzing and evaluating the collecte...read more

My strengths include strong analytical skills, attention to detail, and the ability to work well under pressure.

• Strong analytical skills - able to analyze data effectively and draw meaningful insights

• Attention to detail - meticulous in reviewing and verifying data to ensure accuracy

• Ability to work well under pressure - can handle tight deadlines and high-pressure situations effectively

New drug invention refers to the discovery and development of a novel medication to treat a specific disease or condition.

• New drug invention involves a rigorous process of research, testing, and approval by regulatory agencies.

• It can take years and millions of dollars to bring a new drug to market.

• Examples of recent new drug inventions include the COVID-19 vaccines and treatments for rare diseases like spinal muscular atrophy.

Phase 4 trial is the post-marketing surveillance phase of drug development.

• Phase 4 trial is conducted after a drug has been approved by regulatory agencies.

• It is also known as post-marketing surveillance phase.

• The aim is to monitor the long-term safety and effectiveness of the drug.

• Phase 4 trials involve a large number of participants and can last for several years.

• Examples of drugs that have undergone phase 4 trials include Lipitor and Viagra.

Clinical research is the study of health and illness in people, involving human participants to test new treatments or interventions.

• Clinical research involves conducting studies with human participants to evaluate the safety and efficacy of new treatments, interventions, or medical devices.

• There are typically four phases of clinical research: Phase 1 (testing for safety), Phase 2 (testing for efficacy), Phase 3 (large-scale testing), and Phase 4 (post-marketing surveillance)...read more

Machine learning is a branch of artificial intelligence that enables computers to learn and make predictions without being explicitly programmed.

• Machine learning is a subset of AI that uses algorithms to analyze and interpret data.

• It involves training a model on a dataset to make predictions or take actions.

• There are different types of machine learning, including supervised, unsupervised, and reinforcement learning.

• Examples of machine learning applications include spam filter...read more

SQL explain is a command used to analyze and optimize the execution plan of a SQL query.

• SQL explain provides information on how the database engine executes a query

• It shows the steps involved in processing the query and the order in which they are executed

• The output of SQL explain helps in identifying potential performance bottlenecks and optimizing the query

• Example: EXPLAIN SELECT * FROM table_name WHERE column_name = 'value';

I have intermediate level SQL skills with experience in writing complex queries and optimizing database performance.

• Proficient in writing SQL queries to retrieve, update, and manipulate data

• Familiar with joins, subqueries, and aggregate functions

• Experience in optimizing queries for better performance

• Knowledge of database normalization and indexing

• Comfortable working with large datasets

• Example: SELECT * FROM table WHERE condition;

Window functions in SQL are used to perform calculations across a set of table rows related to the current row.

• Use the RANK() function to assign a unique rank to each row within a partition of a result set.

• You can use the PARTITION BY clause to divide the result set into partitions to rank separately within each partition.

• Example: SELECT column1, column2, RANK() OVER (PARTITION BY column1 ORDER BY column2) AS rank_column FROM table_name;

Dot net is a software framework developed by Microsoft for building Windows applications.

• Dot net provides a common language runtime (CLR) that allows developers to write code in different languages such as C#, VB.NET, and F#.

• It includes a large class library called the .NET Framework Class Library (FCL) that provides a wide range of functionality for developers.

• Dot net also includes tools for developing and debugging applications, such as Visual Studio.

• Examples of application...read more