Monday, April 16, 2007

Scrolling versus Paging

When it comes to the oldest war of the technical formats, you can forget VHS versus Betamax. There's one still raging after more than three thousand years - scrolled versus paged document displays.

Ancient and Medieval documents

In Ancient Egypt, display technology was based on papyrus - the long thin reeds lending themselves to being rolled up into scrolls, rather than sheets. But papyrus decomposes quickly, especially in colder climates, and the Romans invented parchment in the first century BC, made from animal skin, which was more easily folded into paged format.

Parchment was of a more consistent quality, and kept better, but a key advantage was its accessibility - it's much easier to quickly turn to the middle of a book than to the middle of a papyrus scroll.

But pages really came into their own when the printing press was invented, back in the 1400s. Pages could be much better printed on than scrolls, so the quality and efficiency of pages lept ahead of scrolls for more than five hundred years, especially with standard page sizes.

Pros and Cons: the 1950s

I'd summarise three reasons why, by the 1950s, pages were winning the war with scrolls

  • Lower costs, higher quality - due to the printing press
  • Better accessibility - easier to 'flick through' a book than a scroll
  • Standard formats - e.g. letter, A4, and broadsheet sizes introduce economies of scale
Office Computers

The first office computers didn't really challenge the culture of pages. Word processors and presentation software are both inherently paged, because they're designed to be printed onto paper.

But there was a problem - users had differently sized monitors - so in order to fit the page properly on the screen, scroll bars were added.

And computers began to be used in new ways. No amount of paper can replicate automatic formulas in spreadsheets, and emails are not constrained to a certain page width and height. Spreadsheets and emails are scrolled, not paged (that's why they are a pain to print out).

Browsing the web

Most obviously, the web has changed our culture towards scrolling. Browser makers rely heavily on scroll bars and re-arranging content to fit screen size, especially as the mobile web increases display diversity.

There are some interesting exceptions. Google search results are paged (with the top 10 results on the first page, the next 10 on the second page, etc), but this is done to prevent massive amounts of unnecessary data reaching the user, rather than to fit to a certain page width and height.

And many web designers stick to the old mentality, deliberately forcing layout (particularly width) to a certain size. Lazy designers create flash animations or tables that are too big for many screens.

On the web, the word "page" is often used to mean "the document at a given URL". But it's not usually a page, it's a scroll.

Pros and Cons: the 21st century

Nowadays, the cost and quality of paging software is equal to scrolling technology - it's a simple matter of fixing some of the code. Several other factors are more important, and it's clear that scrolls have the advantage:

  • Accessibility - it's easier to 'flick through' a scroll than a page, and it's also easier to adjust to user needs (e.g. increased font size for the visibilty impared)
  • Screen diversity - screens come in such a variety of shapes and sizes that forcing a fixed page width and height will inconvenience many users
There will always be a few exceptions that prove the rule - for example, pages to browse Google search results, or niche applications designed for a small set of users with the same screen sizes.

But it's clear that two thousands years after their last peak, scrolls are once more the leading display technology.

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