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    Databricks Certified Data Analyst Associate· Lessons

    Domain 6 · Lesson 30/39

    Choosing Chart Types for Trends, Proportions, KPIs and Relationships

    Identify the effective visualization type to communicate insights clearly.

    9 min read
    2.56% of exam
    4 sources
    Published 3 Oct 2026
    Docs as of 30 Sep 2026

    What you will be able to do

    • Match a time-based trend to a line, area, bar or combo visualization
    • Tell when a pie chart fits and when it does not
    • Choose a counter for a single headline value and a scatter or bubble chart for relationships between numbers

    Key concept

    The insight decides the chart — Each Databricks visualization type is built for one kind of question: change over time, share of a whole, a single headline number, or the relationship between variables. To pick the effective type, first name the question the viewer is asking, then choose the chart made for it.

    1.Start from the question, not the chart

    AI/BI dashboards come with a large set of visualization types. The dashboard concepts page groups them into chart visualizations (bar, line, area, scatter, pie, combo, funnel and more), table visualizations, statistical visualizations, map visualizations, and specialized ones such as gauges and single-value indicators. Exam questions on this objective almost never ask how to configure a chart. They describe what a stakeholder wants to see and ask which type shows it most clearly.

    So the useful skill is translating. "How has revenue moved month by month?" is a question about change over time. "What share of orders is high priority?" is about proportion. "What is today's total?" asks for one number. "Do longer trips cost more?" asks how two numeric variables relate. The Databricks visualization-types documentation gives a short purpose statement for each chart type, and those statements are what this page is built on.

    Checkpoint 1 of 6· Check yourself

    A stakeholder asks, "Do longer trips cost more?" Which visualization type matches that question?

    Sources1

    2.Change over time: line, area, bar and combo

    Four chart types are described in terms of time. The line visualization is the most direct: line visualizations "present the change in one or more metrics over time." In the documentation's example, the x-axis is the order date with a yearly transform, the y-axis is the average total price, and order priority is mapped to color so that each priority gets its own line.

    Area visualizations "combine the line and bar visualizations to show how one or more groups' numeric values change" across a second variable, usually time. You can stack them, or use 100% Stack, so they also show how the groups add up to a total. The documentation notes that they are often used for sales funnel changes over time.

    Bar charts are the most flexible. They cover change over time, comparison across categories, and proportionality. Their layout can be set to Stack, 100% Stack or Group. Combo charts put the two shapes together: one series appears as bars and another as a line, and each can have its own y-axis. The notebook and SQL editor reference describes them as presenting "the changes over time with proportionality." The AI/BI combo example plots average trip distance as bars on the left axis and average fare as a line on the right axis, with both bucketed weekly.

    Time-oriented visualization types and what each adds
    TypeDescribed purposeLayout options named in the docs
    LineChange in one or more metrics over timeLine shape: Linear, Smooth, Step
    AreaGroups' numeric values changing over time; sales funnel changesStack or 100% Stack; Line shape
    BarChange over time or across categories; proportionalityStack, 100% Stack, or Group
    ComboBars plus a line for two measures on left and right y-axesLeft Y-axis (Bar), Right Y-axis (Line)

    Checkpoint 2 of 6· Check yourself

    An analyst needs one chart that shows weekly average trip distance and weekly average fare together, using a separate y-axis for each measure. Which type fits?

    Sources23

    3.Share of a whole: pie or bar

    When the question is about proportion (what fraction of revenue each priority contributes), a pie works. Its angle encodes a summed measure, such as total price, and its color encodes the category, such as order priority. The documentation also sets a clear limit: pie visualizations "are not meant for conveying time series data." If the stakeholder wants proportions over time, use a bar chart with a 100% Stack layout. Bars show proportionality "similar to a pie visualization," and they still have a time axis.

    Checkpoint 3 of 6· Exam question

    A data analyst builds an AI/BI Dashboard widget that plots a single metric, daily gross merchandise revenue, across every day of the past 12 months, and stakeholders want to spot seasonal upward and downward trends at a glance. Which visualization type should the analyst choose for this widget?

    Checkpoint 4 of 6· Check yourself

    A stakeholder asks for each order priority's share of total price for every month of the year. Which choice follows the Databricks guidance?

    Sources2

    4.One headline number, or how two numbers relate

    Sometimes the insight is a single figure, such as today's revenue. For that, use a counter. Counters "display a single value prominently, with an option to compare them against an offset value." You fill in a Value column and a Comparison column. You can also pick a date column and an aggregation to draw a sparkline in the background. Conditional formatting on the value can color it based on the data. A counter is a deliberate choice: it gives up detail so the one number stands out.

    When the question is whether two numeric measures move together, use a scatter. Scatter visualizations "are commonly used to show the relationship between two numerical variables," and you can map a third dimension to color to compare groups. The notebook EDA tutorial adds that scatter plots can highlight outliers. For a fourth variable, use a bubble chart. Bubble is not a separate type in the picker: you select Scatter and set the Size encoding. The documentation's bubble example plots trip distance against fare, colored by pickup zip and sized by minutes in the taxi. It computes that last value in the dataset query:

    Dataset query for the bubble example. The derived minutes_in_taxi column drives marker size.sql
    SELECT
      *,
      TIMESTAMPDIFF(MINUTE, tpep_pickup_datetime, tpep_dropoff_datetime) AS minutes_in_taxi
    FROM samples.nyctaxi.trips
    LIMIT 500;

    Checkpoint 5 of 6· Exam question

    A dashboard widget needs to show what percentage of total quarterly subscription revenue came from each of four pricing tiers (Basic, Standard, Premium, Enterprise), with the emphasis on the part-to-whole split rather than any change over time. Which visualization type best fits this widget?

    Checkpoint 6 of 6· Check yourself

    In an AI/BI dashboard, how do you create a bubble chart where marker size shows trip duration?

    Sources24

    Exam traps

    Each one states something that sounds right. Open it to see what is actually true.

    1. 1.A pie chart is a good way to show how category shares change month by month.Why is that wrong?

      Pies show proportionality but are explicitly not meant for time series. Use a bar chart, for example with 100% Stack, so the time axis stays.

      Covered in Share of a whole: pie or bar

    2. 2.AI/BI dashboards have a separate Bubble visualization type.Why is that wrong?

      A bubble chart is a scatter whose marker size reflects a metric. You select Scatter and set Size.

      Covered in One headline number, or how two numbers relate

    3. 3.To show one KPI against last period's value, you need a table or a two-bar chart.Why is that wrong?

      A counter shows a single value prominently and can compare it with an offset value, optionally with a sparkline.

      Covered in One headline number, or how two numbers relate

    Sources

    Every claim above is drawn from one of these pages, quoted as it was written on the date shown.

    1. 1.
      “AI/BI dashboards provide a rich library of visualization types to display your data effectively.”
      ↩︎ Start from the question, not the chart
    2. 2.
      “Line visualizations present the change in one or more metrics over time.”
      ↩︎ Change over time: line, area, bar and combo
      “combine the line and bar visualizations to show how one or more groups' numeric values change”
      ↩︎ Change over time: line, area, bar and combo
      “They are often used to show sales funnel changes through time.”
      ↩︎ Change over time: line, area, bar and combo
      “Pie visualizations show proportionality between metrics. They are not meant for conveying time series data.”
      ↩︎ Share of a whole: pie or bar
      “Counters display a single value prominently, with an option to compare them against an offset value.”
      ↩︎ One headline number, or how two numbers relate
      “Scatter visualizations are commonly used to show the relationship between two numerical variables.”
      ↩︎ One headline number, or how two numbers relate
      “Bar charts represent the change in metrics over time or across categories and show proportionality, similar to a pie visualization.”
      ↩︎ Key concept
      “They are not meant for conveying time series data.”
      ↩︎ Exam trap 1
      “Bubble charts are scatter charts where the size of each point marker reflects a relevant metric.”
      ↩︎ Exam trap 2
      “Counters display a single value prominently, with an option to compare them against an offset value.”
      ↩︎ Exam trap 3
      “Scatter visualizations are commonly used to show the relationship between two numerical variables.”
      ↩︎ Checkpoint
      “Pie visualizations show proportionality between metrics. They are not meant for conveying time series data.”
      ↩︎ Prediction
      “In the Layout section, choose Stack or 100% Stack, or Group.”
      ↩︎ Checkpoint
      “To make a bubble chart, select Scatter as your visualization type.”
      ↩︎ Checkpoint
    3. 3.
      “Combo charts combine line and bar charts to present the changes over time with proportionality.”
      ↩︎ Change over time: line, area, bar and combo
    4. 4.
      “For instance, scatter plots can highlight outliers, while time series plots can reveal trends and seasonality.”
      ↩︎ One headline number, or how two numbers relate

    Continue to page 2 of 2

    Choosing Chart Types for Distributions, Cross-Tabs, Flows and Maps

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