Title, labels, and legends in Power BI - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ visualization

intermediate

Identify the Correct Title Placement for Accessibility

You create a bar chart in Power BI showing sales by region. You want the chart title to be clear and accessible for screen readers. Which option correctly sets the title for best accessibility?

A Add a text box above the chart with 'Sales by Region' and disable the visual title.

B Leave the title blank and rely on the axis labels only.

C Set the title text to 'Sales by Region' and enable the 'Title' toggle in the visual formatting pane.

D Use a legend to display 'Sales by Region' instead of a title.

💡 Hint

Think about how screen readers recognize chart titles.

Enabling the visual title with descriptive text ensures screen readers can identify the chart's purpose. Text boxes are not linked to visuals and won't be read as titles.

🧠 Conceptual

intermediate

Purpose of Legends in Data Visualizations

Why is a legend important in a Power BI chart that uses multiple colors to represent categories?

A It automatically filters data based on user clicks.

B It adds decorative colors to make the chart look more attractive.

C It replaces the need for axis labels entirely.

D It explains what each color or symbol in the chart represents, helping users understand the data.

💡 Hint

Think about how users know what each color means.

Legends provide a key to interpret colors or symbols in charts, making data easier to understand.

❓ dax_lod_result

advanced

DAX Measure for Dynamic Title Showing Selected Year

You want a dynamic title in Power BI that shows 'Sales in Year: <selected year>'. Which DAX measure produces the correct title when a single year is selected from a slicer?

Power BI

DynamicTitle =
VAR SelectedYear = SELECTEDVALUE('Calendar'[Year], "Multiple or None")
RETURN
"Sales in Year: " & SelectedYear

A "Sales in Year: " & VALUES('Calendar'[Year])

B "Sales in Year: " & SELECTEDVALUE('Calendar'[Year], "Multiple or None")

C CONCATENATE("Sales in Year: ", FIRSTNONBLANK('Calendar'[Year], 0))

D "Sales in Year: " & MAX('Calendar'[Year])

💡 Hint

Consider which function returns a single value or a default text.

SELECTEDVALUE returns the selected year if only one is selected; otherwise, it returns the default text. VALUES returns a table, causing an error in concatenation.

🔧 Formula Fix

advanced

Fixing Legend Display Issue in a Stacked Column Chart

You created a stacked column chart with categories and subcategories. The legend only shows the main categories, not subcategories. What is the most likely cause?

A The legend field is set only to the main category column, missing subcategories.

B The chart type does not support legends for subcategories.

C The data model has no relationship between categories and subcategories.

D The legend is disabled in the visual formatting pane.

💡 Hint

Check which field is assigned to the legend area.

The legend shows values from the field assigned to it. If only main categories are assigned, subcategories won't appear in the legend.

🎯 Scenario

expert

Designing a Dashboard with Clear Titles, Labels, and Legends

You are designing a sales dashboard for non-technical users. The dashboard includes multiple charts with different measures and categories. Which combination of title, labels, and legend practices ensures the dashboard is easy to understand?

A Use descriptive chart titles, label axes clearly with units, and include legends with clear category names and contrasting colors.

B Use short titles, hide axis labels to reduce clutter, and remove legends to simplify visuals.

C Use generic titles like 'Chart 1', use axis labels only when necessary, and use legends only for pie charts.

D Use no titles, rely on tooltips for labels, and use legends with many colors regardless of contrast.

💡 Hint

Think about clarity and ease of understanding for all users.

Clear titles, axis labels with units, and well-designed legends with contrasting colors help users quickly understand the data without confusion.