How to Select the Right Chart for Your Data

Why is it important to make right chart? Because right charts lead to right decisions. We use charts to tell stories, evaluate alternatives, understand trends or find-out if everything is normal. So, an incorrect charting choice can lead to poor judgment of the messages where as a correct chart can lead to right and faster decisions.

The Chart Making Process: Know the Message Arrange Data Prepare Chart Format

Finding out what you want to say to Compare to show the Distribution to explain Parts of the Whole to tell the Trend over time to find out the Deviations to understand the Relationship

To Compare What it means? You want to compare one set of value(s) with another. Examples: Bar Charts, Column Charts Scatter Plots Pie Charts Line Charts Data Tables

To Show the Distribution What it means? You want to show the distribution of a set of values (to understand the outliers, normal ranges etc.) Examples: Column Charts Scatter Plots Line charts Box Plots

Parts of Whole What it means? You want to show how various parts comprise the whole Examples: Column Charts Bar Charts Pie Charts Data Table

Trend over time What it means? You want to understand the trend over time of some variable(s). Examples: Column Charts Line Charts Data Table

Deviations What it means? You want to see which values deviate from the norm. Examples: Column Charts Bar Charts Line Charts Data Table

Relationship What it means? You want to establish (or show) relationship between 2 (or more) variables Examples: Scatter Plot Line Chart Data Table

2. (Re)arranging the Data Even when we know the message and corresponding chart, sometimes, our data may not support us. We then have to rearrange the data. Using excel formulas, pivot tables, tables and data cleaning tools we can easily massage the data.

3. Prepare the chart Since you have already selected the chart type in Step 1, this is very straight forward. Most of the regular charts are available in MS Excel as default charts. You can insert them with few clicks. But for some special chart types, you may have to prepare the chart by helper series, formatting etc.

4. Format the chart While most formatting is done as per individual taste, there are some ground rules that apply on almost all charts. Here they are: No non-zero axis scale on bar charts [reasons and discussions] Make subtle grid-lines (or remove them) [how to remove grid lines] Add labels to important points [labeling techniques] Add descriptive, bold titles Position axis, scales at the right places (for eg. y-axis to the right on a large time series chart) Use simple, easy colors

A final word: The ideas in this post are meant to be guide lines, not final words in the world of visualization. While these rules can help you make a good chart, a great chart take so much more. Knowledge of your data, Passion for what you do and Genuine focus on your audience’ needs can make your chart truly outstanding.