Using calendar view to see patterns in financial data  

We first released a calendar view with Forestpin Lite early this year, where we visualized daily transaction volume. This was a simple analysis - simple to develop as well as understand.

Calendar view was something we neglected first, but it’s usefulness was realized as we saw different financial data sets visualized in calendar view. When you see a lot of information, covering the entire data set in a single view, you start seeing patterns that you could not see previously.

[Calendar view without annotations](//vpj.github.io/images/posts/calendar.png)
The image above shows two years of transactions visualized in a calendar view, and the image below shows the same with annotations.
[Calendar view with annotations](//vpj.github.io/images/posts/calendar-annot.png)

A few things you can notice,

1. This inactive period is festival season, most companies don’t work for about a week.
2. An unusually high number of transactions for a Sunday, last day of September 2008.
3. The day with most number of transactions, last day of February 2009.
4. Another Sunday!, first day of September 2008.
5. Saturday and Sunday both were busy.

We used it to find irregularities and fraud, so busy weekends at the end of the month suggested some sort of manipulation (invoice settlements we analysed were expected to be spread evenly throughout the month).

This visualization could be improved to show more information. But purely throwing information at the user is not the best idea. Couple of suggestions would be to indicate special holidays and working days - holidays on weekdays and working days on weekends - and may be to split each cell and indicate both the number of transactions and average transaction value in gradients of two different colors.

This is a great example of assisting users to make decisions vs. making decisions for them. It is true that there are software that does a good job at the latter, but undermining the ability of users to recognize patterns is a mistake that most software designers do. Presenting more information well is often better than trying to select the most important bit of information. For instance, if the software was to calculate and present which days look most suspicious (in this case holidays or weekends with a high transaction volume), the user would be losing a lot of information, and the software will be trying to do something the user can do way better.