Metaphors for URLs and Accessibility (24th June 2010)
A couple of somewhat left-field analogies whilst my midn was wandering on my week-long Summer holiday.
As we know, these are like physical addresses. Except that a physical address:
- starts at the smallest target and moves outwards;
- contains information which is mostly (or entirely) outside the property owner’s control;
- owner has more control over the first part than the final parts;
- it starts with the most readable part;
- and it ends with the least readable part.
Contrasting each of those points with URLs:
- starts with the largest target and moves inwards;
- contains information which is mostly (or entirely) within the property owner’s control;
- owner has more control over the final parts than the first part (due to existing domain registrations);
- it starts with unreadable parts (protocol is required; subdomains are optional);
- and it ends with the most readable part (path segment for the current document).
A block of flats somewhat fits the URL model, from the perspective of the building’s owner. Here’s the breakdown for the way URL segments correspond to addresses within a block of flats:
- Postcode and everything else up to the whole building’s location.
- Domain name:
- The building’s location. (The owner chose where to build or where to buy.)
- Path segments:
- Parts of the building, becoming more specific with each level:
- Floor number.
- Corridor name, number or letter
- Flat number and/or letter.
- Room name.
- Fragment identifier:
- Items of furniture with that part of the building.
It’s well worth getting these right. They are literally the location of that resource on the web.
A Jenga tower is a stack of blocks used in the game, Jenga. Players take turns removing blocks from lower levels and placing them on higher levels until the tower topples.
- It stands when each level carries a balanced amount of the overall weight.
- It topples when any level has to carry an amount of weight which is too much, too unbalanced or both.
Toppling is equivalent to inaccessibility. The unfair distribution of weight is equivalent to a layer of the technology stack having to do more than is fair or viable. Such as requiring individual web authors to add text sizing widgets to each and every page of every website they create. Or requiring assistive technologies to develop a sci-fi level of AI to heuristically deduce the semantics of pages using presentational markup.
We can see what the balance should be. Making that happen is the next and ongoing challenge.