These add a dimension to the bar chart, represented by a group of bars or one « cut » bar on the dimension of the horizontal axis.
Stacked mode allows you to effectively observe the evolution of the sum of elements of a dimension, over the dimension of the x-axis (example: time), and gives you an idea of the distribution of elements within that dimension.
Grouped mode compares the parallel evolutions of each element of the dimension, which is shown by a group of bars.
Let's say you want to split your visits over time by type of referral. You want to see on a day-to-day basis if your visits are direct from search engines or from other websites to which your website is linked.
At first glance it’s clear that visits from search engines vary little over time, as opposed to direct visits or referrals, which vary quite a bit more and display an almost parallel evolution.
If we switch to stacked mode, we can see that the proportion between direct visits and referrals is regular over time.
What does this mean? That your visitors already know how to access your website, whether it be by typing the URL or because they know where to find a link?
In order to play around some more with grouped/stacked bars you can head over to the visualization lair at Captaindash.com.
BAR & LINE GRAPHS
The bar & line visualization grants the comparison of many different elements of the same dimension on two common metrics and is effective in exhibiting a time evolution. This method allows you to see the correlation between two metrics.
Let's say you want to see if an ad campaign is effectively translating to greater web traffic and a higher number of visitors viewing your content. Adding a line representing your website bounce rate shows you whether your paid visits are efficient or if your visitors just leave your website as soon as they arrive.
At a glance, we can see that even if your paid visits vary dramatically, your bounce rate remains relatively consistent over time. You can still see, however, that the slight curve in the bounce rate correlates to the evolution of visits over time. The higher the amount of paid visits, the higher the bounce rate (and vice versa).
So is your campaign worth it? Oh, and keep an eye on your bounce rate...it seems to be increasing over time.
In order to play around some more with bars & line graphs you can head over to the visualization lair at Captaindash.com.