Exceeding the Boundaries of a Single Screen
My insistence [is] that a dashboard should confine its display to a single screen, with no need for scrolling or switching between multiple screens...
-- Few, Information Dashboard Design, Ch. 3.1
First, what does this mean in a post-mobile revolution world? Many devices no longer have screens big enough to fit a traditional dashboard. Refusing to make online applications mobile compatible is simply no longer an option given the ubiquity of devices. What are we left with? We need to find a way to provide meaningful data for our dashboard viewers without necessitating side-by-side visual comparison. We need to use dynamic, flexible layouts such that when viewers are on a smaller device, their screen renders content in a way that best uses their screen real estate. Finally, we need to make sure that we are presenting data in ways that allow for meaningful comparisons to be made. Given the plethora of data manipulation libraries, we have no excuse not to slice, dice, and aggregate the underlying data to facilitate viewers' analysis.
What about the cases where viewers are using devices that do have sufficient screen real estate to make a meaningful one-page layout? It used to be the case that many well-designed web pages also followed this steadfast rule: keep your content to a single page to avoid the burden of having your user scroll down the page. Additionally, if we had too much content on one page, it took a long time for content to load which created a sub-par experience.
Now that we have the ability to widely make asynchronous requests (e.g. with Ajax), this is not as much of an issue. Users are also used to web applications that make use of infinite scrolling -- scrolling is a more natural part of the online user experience than it was even 5 years ago. To put it in the language that Donald Norman from The Design of Everyday Things uses: the nature of the browser environment's affordances have changed. Browser users have always been able to scroll through a web application. Nowadays, though, browser users are aware that they can scroll easily, and use this as a primary method to interact with web applications, whereas before it was a secondary method.
Does this mean that we should let our dashboards grow into multi-page mammoths? No. The point of a dashboard should still be to succinctly provide informative data. There is more justification, though, to think about extending the dashboard boundary beyond the edge of the page when it is necessary.