Critical thinking is your nature, statistics is your strongest language, and data analysis is your passion. After years of working towards your goal, you’ve finally been shortlisted for your dream job. Or you’re a newbie and just trying to enter this fascinating world of data analysis. Either way, at some point or the other, you will come across the Power bi software by Microsoft. As salt is to food, Power bi is to data analytics. The necessary element to ace any interview and succeed in this field. Preparing for an interview or reading only out of curiosity to gain knowledge, this article would be the perfect guide for all the data analysts out there. So, we will discuss the commonly asked Power Bi Interview Questions in this article for you.
What kind of Power is ‘Power Bi’?
If you’re new to this field, I am sure you must be thinking ‘what is this Power Bi’? Don’t worry I won’t let you stay in the dark. In simple words, Power Bi is the power to conduct data analysis at superhuman speeds. It is a collection of several software services and applications developed to conduct data analysis. The software caters to various roles and responsibilities and can be used to complete a plethora of tasks.
Here’s an example to illustrate how important Power Bi is in this field. You have a long excel sheet with figures all over, too boring to read. Use Power Bi to convert it to visually appealing graphs and reports. Need to form a report in your company’s app? Combine the data in Power Bi and Viola! Your report is ready. In short, it is the go-to solution for every problem analysts encounter.
Now that you know what Power Bi is, let us move to the next step – the dreaded interview. You are confident that you know enough about the software and you know your way of navigating through it. But who knows what you will be asked in the interview? How do you answer the questions in the best possible way?
A Short Guide to Power Bi Interview Questions
The following is a list of questions that you might expect about Power Bi, in any interview for the post of a data analyst. Learn how to answer them and ace your interviews and your jobs.
- What is Power Bi?
One of the most basic questions. You can answer this in brief by talking about how the software is a collection of several other software services and applications that cumulates information in different forms and converts and transforms them into visually appealing and clear presentations. The software is used by companies to form their client reports and share them with the stakeholders easily. It is a software service that can extract valuable information from multiple sources and combine them into one.
- Where is Power Bi used in the professional world?
With its wide range of functions, the Power Bi software service is used to cater to many professional services. To name a few:
- Project Management Departments – A software system like Power Bi is useful for keeping a track of the performances and previous records of employees part of a project and to be informed about the current progress.
- Business and Data Analysts – The job of a data analyst is to analyze the data of thousands of businesses and then form a report accordingly. The professionals who do this job quicker and more efficiently than the others have an edge. Power Bi lets the data analysts do just that. Thus, it becomes a handy tool for them.
- Database Administrators – The functions and features of Power Bi, especially PowerShell make the task of distributing tasks and providing special access to reports easier. Database administrators can use Power Bi to control and assign access to reports to the people designated for the role.
- What are the major elements of Power Bi?
Power Bi can be used to perform all kinds of duties. To fulfill such a variety of demands, the software service has the following elements:
- The Power Pivot – This element collects all the data and combines it in the same format.
- The Power Query – This element allows the users to work on the data collected through the Power Pivot.
- The Power Q&A – This unique feature makes the job of users easier by letting them interact with the data in English and finding quick answers to get the job done.
- The Power View – Users can use this element to create graphs, charts, maps, and other visual depictions of their data reports.
- The Power Map – With huge datasets covering multiple locations, this component comes into use. It enables the users to process the different geographical locations in their data.
- Why would you choose Power Bi over any other Bi tool?
Microsoft’s Power Bi has several better features when compared to other Bi tools. One of the most apparent advantages is the fact that Power Bi is capable of converting data from different sources and combining them in one to ease the working. The software service also allows real-time updates in the dashboard. Another unique feature that gives Power Bi an edge is the Q&A feature that makes the process of data exploration quick and easy. As a Microsoft product, the software is compatible with all other Microsoft tools, making data transfers efficient.
- What are the fundamental units of Power Bi?
Power Bi constitutes the following units for users to work on their data in a systematic and visually appealing manner:
- Visualizations – One of the greatest advantages of Power Bi is the presence of options of visual representations of data including line graphs, pie charts, bar graphs, maps, etc.
- Datasets – Power Bi makes use of datasets of different types – excel sheets, CSV files, tables, documents and many other options. Users can work over most kinds of datasets using Power Bi.
- Reports – Using Power Bi, users create reports that are a collection of visualized datasets on one or multiple pages.
- Dashboards – These are the single-layered presentations that condense the data into single-page visualizations.
- Tiles – Each visualization or one aspect of the required data is called a tile. These can be any of the visualizations used.
- What functions can the users perform with the Power Query?
The Power Query editor allows the users to work and perform operations on the data they have collected. There are majorly four main functions that the Power Query feature performs. These functions are listed under four tabs:
- Home Tab – This allows the users to preview the data collected and manage the rows, columns, headings, etc of the data. They can choose to reduce the number of rows and columns or group the data into several tables etc as per their needs.
- Transform Tab – Using this tab, the analysts can change the data according to their convenience and perform the R Script and queries on the data. They can replace values, fix errors, or use any other statistical tool they want to on the data.
- Add Column Tab – This tab allows users to add new columns customized by them based on their information and the statistical data and other requirements. The users can either add a custom column, add a conditional column or perform functions on numerical columns.
- View Tab – This tab lets the users choose if they want to view the Query Editor settings. The advanced editor tab can also be opened from here to edit any query code.
- What is DAX? What are the advantages of using variables in DAX?
DAX or Data Analysis Expressions is a functional language used in several data visualization tools like Power Bi. It is used to perform calculations and data analysis on the data stored in the software service. There are 5 kinds of data types of DAX – numerical, boolean, date time, string, and decimal. Using variables in DAX has several advantages:
- The variables can be used multiple times in DAX queries, helping the users avoid any additional queries in the source data.
- Variables make DAX expressions more useful, logical, and understandable.
- If given a Power Bi report, how will you analyze it in Excel?
To analyze a Power Bi report in Excel, there are a few steps to be followed:
- The first step is to select the option of ‘Analyze’ in the settings of the Admin Portal. It should be ensured that the Administrator has enabled the option of Excel.
- The next step is to install Excel updates from the settings.
- Once done, navigate to the workspace and select the option of ‘Analyze in Excel’ after selecting the dataset
- Download the file and save it.
- To continue, the users need to provide their Power Bi ID and password.
- What are in your view some drawbacks of using Power Bi?
Even though Power Bi is a great tool for all professionals, it does have its drawbacks.
- Reports and dashboards prepared using Power Bi can only be shared with identical email domains which draws a limitation to the accessibility of data.
- The dashboard does not accept user, account, or other parameters
- The software does not mix imported data accessed from real-time connections
- What are the different connectivity modes used in Power Bi?
To work using Power Bi users can use three kinds of connectivity modes:
- SQL Server Import Mode – This is the most widely used connectivity mode in Power Bi. It allows the users to access and make use of the full capabilities of the Power Bi desktop version.
- Direct Query Mode – This mode is used when the dataset exceeds the file size recommended by the software. In such a case, users can use the DIrect Query mode which saves the metadata of the source and uses that while executing queries.
- Live Connection Mode – When users use this mode, the data is not saved in Power Bi. Instead, all interactions with the report query the Analysis Service. However, only 3 data sources are compatible with the live connection in Power Bi – The SQL Services Analysis, Azure Analysis Services, and Power Bi Datasets.
- What are the steps to follow to open the Data Stories Gallery in Power Bi?
The first step is to open Power Bi in your browser. Next, users need to hover for a bit on ‘Learn’ and select communities from there. After scrolling down, there is the option of ‘Data Stories Gallery’ where users can add their stories as well.
- What kind of data sources can Power Bi connect to?
Power Bi has a wide range of data sources that it can connect to. These sources can be divided into a few categories –
- Files – These are the datasets in document files such as Excel sheets, Power Bi desktop files, and all documents saved in the CSV formats.
- Content Packs – These are the groups of related documents saved together as one. These packs can also be of two kinds – those from service providers such as Google Analytics, and those that are shared by other users in the organization.
- How will you compare the features of Power Bi with that of Tableau?
There are a few differences between the features of Power Bi and those of Tableau.
- Power Bi can only handle a limited number of datasets as compared to Tableau, which can handle a huge number of datasets without affecting its performance
- Power Bi has a user-friendly interface that is easy to learn and can be used by naive as well as experienced users. In comparison, Tableau is a more complex interface that can only be used by experienced professionals.
- Power Bi uses Data Analysis Expression to build formulas and variables while working with the data. Tableau uses Multidimensional Expressions to perform higher-level calculations on the datasets.
- What is the use of Power Bi Designer?
As part of the Power Bi Umbrella, the Power Bi Designer is used to create visual reports. This is the tool used by professionals to create interactive and visual representations in the form of dashboards and reports. The users can change the data format according to their needs and structure the layout of the reports. It can be used as a stand-alone application as well. The Power Bi Designer has a drag and drop format with several options to modify their data as well as the structure of their report.
- What is the difference between calculated columns, calculated tables, and measures?
The differences between calculated columns, calculated tables, and measures are as follows:
- Calculated columns are added to tables using the existing data. Calculated tables are created to define values. Measures are used to create complex calculations.
- Calculated columns are used when data sources do not contain the data in the required format. Calculated tables work well for calculations and for data that users want to be stored. Measures are used for highlighting totals, comparing sales, forecasting sales, etc.
- DAX formula defines values in new columns in calculated columns. There is no querying of data sources in calculated columns. Calculated tables and measures on the other hand are created in data reports and dashboards.
- What is Row-level security in Power Bi? How can users implement it?
The row-level security is a feature that restricts the use of the datasets by people. Using filters, users can define the rules and roles within the desktop system and publish them. There is also a feature to restrict the tabular data to the user with the username function. The row-level security, however, is available only to Power Bi Pro subscribers.
- How to manage roles in Power Bi?
The steps that need to be followed to manage roles in Power Bi are:
- Import the dataset in the Power Bi Desktop
- Select your connection
- Select the Modeling tabs and then select the option of manage roles
- Then select create and give a name to your role
- Select the table you want to apply the DAX rule to
- Enter the relevant DAX expressions
- After entering the expression, validate it by selecting the checkbox above the expression
- Save the document
Once saved, the role will be applied to the selected data in the report in Power Bi.
- What are the different forms of gateways provided in Power Bi?
There are three kinds of gateways in Power Bi:
- On-premise data gateway – This gateway allows multiple users to connect to several on-premise data sources. Users can use this gateway on all supported devices with one installation. It is used by people who need to share their reports and need multiple professionals to work on them.
- On-premise data personal gateway – This gateway is for personal use only. Users can connect to various sources themselves but they cannot share them with others. This gateway is used by professionals who need to create reports but do not need to share them with clients or other professionals.
- Virtual network data gateway – This is another public use gateway that allows multiple users to connect to several data sources. However, these data sources need not be on-premise data sources, they can be secured by virtual networks.
- What is the difference between a Dashboard and a Report?
Although dashboards and reports are both visual representations of the datasets with several tiles, there are a few differences between the two.
- A dashboard is only of one page whereas a report can be of several pages
- A dashboard can have tiles from several datasets or reports whereas a report only has a single dataset.
- Dashboards have the option to set email alerts for people whereas reports do not.
- Dashboards do not have the option to view or access the underlying datasets and tables. Reports allow the users to view the datasets, values, and tables.
- What are KPIs in Power Bi?
KPIs or Key Performance Indicators evaluate the company’s performance in specified areas, using measurable goals and values. It has a base value which is later compared to the target value. These indicators can also be represented graphically. These KPIs prove to be a great way to analyze the performance of employees and understand the progress of the company by knowing if the set goals have been met or not.
- In your opinion, why is the job of a data analyst important?
With the world booming with business, there is a huge amount of available data to professionals. However, data is not of much use if it is not put to use. Therefore, the job of a data analyst is important as it allows the data to be put to proper use for the growth of the businesses. An in-depth analysis of the data about the progress of a business, customer demands, employee performances, etc., gives the companies an edge to build their strategies and put forward their products in a better light. In such a scenario, the job of a data analyst becomes more important as it builds the foundations of any company.
Data analytics has emerged to be one of the most important job positions in the corporate world. For all newbies and even experienced professionals in this field, the knowledge of a revolutionary software system like Power Bi is the foundation of their career. Job interviews, debates, and all other conversations about data analysis require a good knowledge of the system. The article is a short guide for all those interested in this field to ace their interviews and prove themselves smart nerds in their fields.
The questions provided here range from the basic information such as what the software service is, its components, its functions to the more in-depth information about Power Bi. This guide with the basic interview questions and their answers will be the much-needed first step for all the people looking to enter this technical field. The questions will help the potential candidates be better prepared for their job interviews and their careers ahead. If you’ve read so far, congratulations, you are now ready to face your dreaded job interview. With the knowledge of the efficient Microsoft tool, you can now excel at your job responsibilities with Power Bi.