A friend of mine, Graham Jones, is writing an article on the psychology of website navigation and asked me to give my views on the accessibility of website navigation. This seemed an ideal prompt for a blog.

Initially, I thought of website navigation solely as the hierarchical menu structure or the site map, but I quickly realised it should cover all tools and techniques that enable a user to get from where they are to where they need to be on the web site.

This became too much for a single blog so I have written a series of three:

• The first (this one) covers various menus.
• The second covers: site maps, links and hot spots.
• The final covers: search, skip-tos and access keys.

I will look at each technique in turn and consider how they can be used to enhance the accessibility of a site and when they can make things worse.

Menus

Menus are probably the most common form of navigation.

The first menu type provides links to the main sections of the site and remains constant across all pages; it is normally at the top and is at the beginning of the tab order of the page. This is an important accessibility feature for all users as it not only provides quick access to the relevant areas but it should give a clear view of what the site owner believes the site is about. Having a clear view of the structure is important for any user but for people with vision impairments being able to build up this mental image is really important.

One special entry in the main menu is 'home'. This is important for accessibility as it is an escape route; if someone gets lost in the site they can go to 'home' and start again. It has become customary to have the company logo in the top left hand corner of the a page and to have this a link to home, this custom should be followed as it aids the accessibility/usability of the site.

The next menu on most pages is at the bottom and includes terms and conditions, privacy etc. Amongst this group should be an accessibility statement. This statement should be the last item in the list so that users who are interested in it can find it easily by back-tabbing when they first enter the page. An alternative is to make it the first tab, before the main menu. This makes it very visible but it also means that the user has to tab across it every time they are trying to get to the menu or content.

The third menu type is a submenu which provides a guide to the next level down in the site hierarchical structure. This can either be visible on the page (often down the left hand side) or as a drop-down menu from the main menu. Unfortunately, many drop-down menus are a nightmare for screen reader or non-mouse users. Try navigating through the menus without using the mouse (just use the tab button); one of two things might happen. You will not be able to get to the sub-menus at all and will just skip across the main-menu. You will tab through all the sub-menus, very often without actually being able to see them, and give up in disgust.

It is now considered best practice to include a header (see part two) with the menu type just before each menu. A screen-reader user can get a list of headings and quickly navigate to the right menu.

Having said that menus are an essential accessibility aid, it has also to be said that they are a real barrier to accessibility because they have to be navigated before the user gets to the the real content of the page. The solution to this is to have skip-to fields (see part three) near the top of the page.

Part two of this series is here.