4E. Perform analytics in Power BI

Question 1

What is a key dependency for Power BI when it comes to using advanced analytics?

Answer 1

The answers are only as good as the underlying data.

Question 2

What is statistical summary?

Answer 2

Exploring the statistical summary gives the user a high-level view of the available data, where they can see clusters, patterns on behavioral data, data averages, and more. They can gain insights about their data that will help drive business decisions.

Question 3

How can you extend the statistical capabilities of Power BI?

Answer 3

By using statistical programming languages such as Python and R.

Question 4

What are the most common visuals to display statistics, and how do you create them in Power BI?

Answer 4

• Histograms – you can represent a histogram with one of the bar or column chart visuals.
• Bell curves – you can represent a bell curve with an area chart visual.

To cover intervals in a “bar chart” histogram, use Groupings/Bins.

Question 5

What can TOPN analysis be good for?

Answer 5

The Top N analysis is a great way to present data that might be important, such as the top 10 selling products, top 10 performers in an organization, or top 10 customers. Alternatively, you can look at it from the other perspective and present the bottom 10 items in a list, in other words, the worst performers.

Question 6

What are the three ways of showing Top N in a report?

Answer 6

• Q&A visual (ask for the visual, and then save it)
• Top N filter
• DAX formula

Question 7

What is the DAX TOPN function, and when might it be preferable to other ways of showing Top N?

Answer 7

This option could be useful if you want to present the top 10 in a different context, such as how much of the top 10 best-selling products contributed toward the overall total sales.

For example, start by creating a new measure called Top 10 Products. Then, use the TOPN function, along with the SUMX function, to calculate your top 10 products by total sales, as follows:
Top 10 Products =
SUMX ( TOPN ( 10, Product, Product[Total Sales]), [Total Sales] )

Question 8

What is important about outliers?

Answer 8

You will want to identify outliers to isolate data points that significantly differ from other data points, and then take action to investigate the reasons for the differences. The results of this analysis can make a significant impact on business decision making.

Question 9

In what ways can you identify outliers?

Answer 9

• By visuals, for example a scatter plot is a good option.
• DAX, for example using CALCULATE AND FILTERS

Question 10

What’s the difference between grouping and binning?

Answer 10

• Grouping is for categories of data.
• Binning is similar to grouping, but is used for continuous fields such as numbers and dates.

Question 11

How can you create groups and bins?

Answer 11

• In the Fields pane, right-click the data field that you want to analyze and then select New Group. You can also select several “groups” in a visual, right-click, and click New Group.
• Select your option in Group type for either List (categorical) or Bin (numerical)
• The group/bin then appears in the fields pane and you can use it in visuals, for example in a Legend well.
• To edit the group, right-click the field.

Question 12

What is the difference between grouping/binning and clustering?

Answer 12

The Power BI clustering feature allows you to quickly find groups of similar data points in a subset of your data. It analyzes your semantic model to identify similarities and dissimilarities in the attribute values, and then it separates the data that has similarities into a subset of the data. These subsets of data are referred to as clusters.

With grouping/binning, you decide what goes into a group or bin.

Two create clusters, click the More option in the visual header.

Like with groups/bins, clusters appears as a new field in the fields pane that you can use to cross-highlight or as a legend in other visuals.

Question 13

From what visuals can you create clusters, and how do they differ?

Answer 13

For example:
- Scatter chart
- Table

With the cluster chart, you can only find clusters by two measures. If you want to find clusters by using more than two measures, you can use a table visual instead, add all the fields you want to use, and then run the clustering algorithm by using the same process.

Question 14

What are examples of visuals that are good for conducting time series analysis?

Answer 14

• Scatter chart
• Area chart
• Line chart

Question 15

What should you consider before using a custom visual?

Answer 15

Some organizations prefer not to use custom visuals for security or other reasons. Before you import custom visuals, check with your organization to see if they are allowed or not.

Question 16

What are ways of enhancing time series analysis?

Answer 16

By using a play axis.
- You can download a custom Play axis visual which you can use to “play” visuals on an entire page.
- If not downloading, you can also use the Play axis field on the default Scatter chart.

Question 17

What are some good uses for the Analyze feature?

Answer 17

The Analyze feature provides you with additional analysis that is generated by Power BI for a selected data point. You might want to use this feature to determine if Power BI has found something that you haven’t seen before, or if you want Power BI to give you a different insight into your data. This feature is particularly useful for analyzing why your data distribution looks the way that it does.

Question 18

When does the Analyze feature not work for a visual?

Answer 18

This feature does not work if you have
- non-numeric filters applied to your visual and/or if you have
- measure filters applied.

Question 19

How do you use the Analyze feature, and what are your two options?

Answer 19

To use the Analyze feature,
- right-click a data point on the visual and then hover over the Analyze option to display two further options:
- Explain the increase and
- Find where the distribution is different. (this one tells you which filters cause a distribution to vary the most)

The options that are available will depend on the data point that you selected.

If you find this analysis useful, you can add the new visual to your report so that other users can view it. Select the plus (+) icon in the upper-right corner of the visual to add it to your report.

Question 20

What are what-if parameters, and what are two uses for them?

Answer 20

You can use what-if parameters to run scenarios and scenario-type analysis on your data. What-if parameters are powerful additions to your Power BI semantic models and reports because they enable you to
- look at historical data to analyze potential outcomes if a different scenario had occurred. Additionally, what-if parameters can help you
- look forward, to predict or forecast what could happen in the future.

You can use what-if parameters in multiple situations, such as to determine the effect of increased sales to deeper discounts, or to let sales consultants see their compensation if they meet certain sales goals or percentages.

Question 21

What are the basic steps to creating and using a what-if parameter?

Answer 21

• Go to the Modeling tab and select New Parameter.
• On the What-if parameter window, configure the new parameter.
• Make your settings
• Two objects will appear in the field pane: the parameter (which can be used for the slicer) and a measure which can be used to display the value of the parameter (for example on a card visual).
• To use the parameter, create a new measure that references it so that its value adjusts with the slicer.

Question 22

Which are the three main specialized/AI visuals?

Answer 22

• Key influencers
• Decomposition tree
• Q&A

Question 23

What is a good tip when using any AI visual?

Answer 23

When adding an AI visual to your report, make sure that you size it to become as large as possible. That way, report consumers can fully interact with and explore the data in the visual.

Question 24

What does the Key influencers visual do?

Answer 24

The Key influencers visual helps report consumers understand the factors that drive a particular metric, like sales revenue. By using AI, Power BI will analyze the data, rank the factors that matter, and then present them as key influencers.

Additionally, you can click on the Top segments tab, where AI groups data by key influencers into segments to find key influencer combinations with powerful impact on the variable in question.

Question 25

What does the decomposition tree visual do, and what is it good for?

Answer 25

The Decomposition Tree visual helps report consumers visualize data across multiple dimensions. It automatically aggregates data and enables consumers to drill down into dimensions in any order. As a result, it’s a valuable tool for
- ad hoc exploration and
- conducting root cause analysis.
As an AI visual, a decomposition tree provides a guided exploration experience that helps by finding the next dimension for consumers to drill down into.

When clicking a group in a dimension you can decide which dimension to explore next, or tell the AI to figure out which dimension yields a group with either the highest or lowest value.

Note that report authors can lock which dimension is used for the top level.

Question 26

What is the Q&A visual?

Answer 26

The Q&A visual allows report consumers to ask questions of their data and receive responses as data visualizations. Similar to how web search engines parse and understand complex search requests, report consumers can write natural language questions (in English).

Question 27

How can you ensure that the Q&A visual is user friendly?

Answer 27

To optimize the Q&A experience:
- Ensure that the data field names are user-friendly.
- Enhance the semantic model with synonyms and terms.
- Additionally, you can hide fields, such as fields that are used in model relationships, to restrict their use in Q&A.
- You can also add suggested questions that become prompts in the Q&A visual.

Question 28

What are the main settings categories when click the cog wheel in the upper right corner of the Q&A visual?

Answer 28

• Field synonyms
• Review questions (that users have asked)
• Suggest questions
• Teach Q&A (to understand terms and questions users might ask)