Why Bar charts (horizontal and vertical) in Tableau? - Purpose & Use Cases

The Big Idea

What if you could instantly see your best-selling product without reading a single number?

The Scenario

Imagine you have a list of sales numbers for different products written down on paper. You want to compare which product sold the most, but you have to scan through all the numbers manually.

It's hard to quickly see which product is the best or worst just by looking at rows of numbers.

The Problem

Manually comparing numbers is slow and tiring. You might make mistakes reading or adding them up. It's also hard to spot trends or patterns when everything is just text or numbers in a table.

This makes decision-making frustrating and time-consuming.

The Solution

Bar charts turn numbers into simple bars that you can see and compare instantly. Horizontal or vertical bars show which values are bigger or smaller at a glance.

This visual approach makes understanding data fast, easy, and less error-prone.

Before vs After

✗ Before

Product A: 120
Product B: 80
Product C: 150

✓ After

Bar Chart:
|■■■■■■■■■■■■■■■■■■■■| Product C (150)
|■■■■■■■■■■■■■■| Product A (120)
|■■■■■■■■| Product B (80)

What It Enables

Bar charts let you quickly spot the highest and lowest values, making data-driven decisions easier and faster.

Real Life Example

A store manager uses a vertical bar chart to see which product categories sold the most last month, helping decide what to stock more.

Key Takeaways

Manual number comparison is slow and error-prone.

Bar charts visualize data clearly with horizontal or vertical bars.

This helps you understand and act on data quickly.

Practice

1. Which of the following best describes a vertical bar chart in Tableau?

easy

A. Dimension on Columns and Measure on Rows

B. Dimension on Rows and Measure on Columns

C. Both Dimension and Measure on Rows

D. Both Dimension and Measure on Columns

Solution

1. Step 1: Understand vertical bar chart layout

   Vertical bars are created by placing the dimension on Columns and the measure on Rows in Tableau.

2. Step 2: Match the layout to options

   Dimension on Columns and Measure on Rows matches this layout exactly.

3. Final Answer:

   Dimension on Columns and Measure on Rows -> Option A

4. Quick Check:

   Vertical bars = Dimension on Columns, Measure on Rows [OK]

Hint: Vertical bars: dimension columns, measure rows [OK]

Common Mistakes:

• Confusing horizontal and vertical bar chart layouts
• Placing both dimension and measure on the same shelf
• Swapping rows and columns incorrectly

2. Which Tableau shelf placement creates a horizontal bar chart?

easy

A. Dimension on Rows, Measure on Columns

B. Dimension on Columns, Measure on Rows

C. Measure on Rows only

D. Dimension on Rows only

Solution

1. Step 1: Recall horizontal bar chart setup

   Horizontal bars are made by placing the dimension on Rows and the measure on Columns.

2. Step 2: Identify correct option

   Dimension on Rows, Measure on Columns matches this setup exactly.

3. Final Answer:

   Dimension on Rows, Measure on Columns -> Option A

4. Quick Check:

   Horizontal bars = Dimension on Rows, Measure on Columns [OK]

Hint: Horizontal bars: dimension rows, measure columns [OK]

Common Mistakes:

• Mixing up rows and columns shelves
• Placing only measures without dimensions
• Choosing options with missing shelves

3. Given a dataset with 'Category' as dimension and 'Sales' as measure, what will be the result of placing 'Category' on Rows and 'Sales' on Columns in Tableau?

medium

A. A scatter plot comparing categories and sales

B. A horizontal bar chart showing sales per category

C. A line chart showing sales trend

D. A vertical bar chart showing sales per category

Solution

1. Step 1: Analyze shelf placement

   Category on Rows and Sales on Columns creates vertical bars representing sales per category.

2. Step 2: Identify chart type

   This layout produces a vertical bar chart, not horizontal or other chart types.

3. Final Answer:

   A vertical bar chart showing sales per category -> Option D

4. Quick Check:

   Category rows + Sales columns = vertical bars [OK]

Hint: Category rows + Sales columns = vertical bar chart [OK]

Common Mistakes:

• Assuming horizontal bars instead of vertical
• Confusing bar chart with line or scatter plot
• Ignoring shelf placement rules

4. You created a bar chart but the bars are vertical when you wanted horizontal bars. What is the most likely fix?

medium

A. Remove the dimension from the view

B. Change the mark type to Line

C. Swap the dimension and measure between Rows and Columns shelves

D. Add a filter to the data

Solution

1. Step 1: Identify cause of vertical bars

   Vertical bars appear when dimension is on Rows and measure on Columns.

2. Step 2: Fix by swapping shelves

   To get horizontal bars, swap dimension to Columns and measure to Rows.

3. Final Answer:

   Swap the dimension and measure between Rows and Columns shelves -> Option C

4. Quick Check:

   Swap shelves to switch bar orientation [OK]

Hint: Swap dimension and measure shelves to change bar direction [OK]

Common Mistakes:

• Changing mark type instead of shelf placement
• Removing dimension causing no bars
• Adding filters unrelated to orientation

5. You want to create a dashboard showing sales by region with horizontal bars, but also want to add a vertical bar chart showing profit by region side by side. How should you set up the shelves for each chart in Tableau?

hard

A. For sales: Dimension on Columns, Measure on Rows; For profit: Dimension on Rows, Measure on Columns

B. For sales: Dimension on Rows, Measure on Columns; For profit: Dimension on Columns, Measure on Rows

C. For sales: Dimension on Columns, Measure on Columns; For profit: Dimension on Rows, Measure on Rows

D. For sales: Measure on Rows, Dimension on Rows; For profit: Measure on Columns, Dimension on Columns

Solution

1. Step 1: Set up horizontal bar chart for sales

   Horizontal bars require dimension on Rows and measure on Columns.

2. Step 2: Set up vertical bar chart for profit

   Vertical bars require dimension on Columns and measure on Rows.

3. Step 3: Match options to setup

   For sales: Dimension on Rows, Measure on Columns; For profit: Dimension on Columns, Measure on Rows correctly assigns shelves for both charts.

4. Final Answer:

   For sales: Dimension on Rows, Measure on Columns; For profit: Dimension on Columns, Measure on Rows -> Option B

5. Quick Check:

   Horizontal bars = dim rows, measure columns; Vertical bars = dim columns, measure rows [OK]

Hint: Horizontal bars: dim rows; Vertical bars: dim columns [OK]

Common Mistakes:

• Using same shelf setup for both charts
• Placing measures on wrong shelves
• Confusing dimension and measure roles