When we have lots of data, we try to summarize it by calculating the average. As they say, averages are mean, they do not give away much.
I want to share with you an interesting example from Amazon.com on how they give more details by combining average with distribution.
As you might know, Amazon shows the rating of each of the products they sell. Customers & users rate the products from 1 to 5 stars. When you visit the product page you will see the average rating. But there is a small down-arrow next to it. When you click on it, Amazon shows you the break-up of that rating so you have a better idea of how the ratings are split.
Why show distributions?
Showing distribution of values corresponding to the average reveals important information about the data. We tend to use averages alone since they take very little time to compute and very little space to show. But adding the ability to show distribution of values (on demand) is a powerful way to let end-users understand the data better. [related: calculating frequency distributions in excel]
Below, I have shown a demo of how you can do this using Excel. Tomorrow, I will write a tutorial explaining the same.
On-demand Details in Excel Charts – a Demo:
What is your Opinion – Averages / Distributions / Both or Something else?
I prefer to use simple metrics like average, median, sum, count, min or max at the high-level in my dashboards or charts. But I always add extra detail by showing distribution of values or break-up by a different parameter so that my audience can understand the outputs better.
What about you? What metrics do you use at high-level and how do you add detail? Please share your thoughts and techniques using comments.
More Charting Principles:
There are tons of very good charting examples around us. Once in a while, I write about these on chandoo.org. I recommend reading the below articles if you make charts,
5 Responses to “Preparing Profit / Loss Pivot Reports [Part 2 of 6]”
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I am not getting sound from the videos. I have checked all the settings and spent several hours searching the Internet to no avail.
Has anyone else had this problem?
Is there anyway to get the Grand Total to be broken out in the same fashion as the items above it? For instance, if you have in column 1, widget a, widget b, and have their sales by month in column 2, I'd like to see the grand total also be by month, for widget a & b combined.
I can't get anything other than a single line for the grand total, rather than the same format as the data above.
Widget A Month Sales
Jan 100
Feb 200
Widget B
Jan 150
Feb 250
Grand total - here I would also like to have Jan, Feb.
Jan 250
Feb 450