A scenario

Ok, you're a blind or visually-impaired person who, like all the rest of us, needs to do their weekly shopping.

One option is to use an online shopping site such as Tesco's excellent Access site (http://www.tesco.com/access/) which interfaces brilliantly with screenreaders and is generally a very accessible and nice-to-use site. However online shopping isn't everyone's thing, and indeed we need to reach out to the possibly large number of blind people who don't even use computers on a regular basis. How many sighted people do all their shopping online each week?...

The other option is to make your way to the nearest store using either your cane or a guide dog if you have one. Once in the store, finding the items you want whilst avoiding other customers and obstacles isn't an easy task (even for a sighted person) and given how supermarkets love to change the layouts of their displays at a moment's notice in order to increase sales, could leave a blind user very confused when suddenly what they thought was the fruit and veg aisle turns out to be lingerie...

I have a number of blind and partially-sighted friends who have agreed to talk with us about the difficulties they face doing tasks like this that many people take for granted. Mike is a partially-sighted student at Birmingham University. His sight is good enough to navigate without a cane in daylight but indoors in a crowded environment is more of a challenge. Even if he is able to locate an aisle on his own, there is no way for him to find the actual items he's interested in or the prices, special offers etc. without asking a nearby customer or assistant.

Using a cane in a crowded environment such as a supermarket can be awkward too. Mike recalls with much amusement the episode where he inadvertantly ran his cane up a girl's leg, thinking it was a lamp post, until the resulting scream told him otherwise. The visibilty of the cane is a big feature of its usability as it warns people to steer clear and give the user space, however not everyone is observant and a quick clip round the ankles from a blind person in a hurry is not uncommon in a crowded supermarket.

So we seek to address these issues - and any more we come across through our talks with Mike and friends, the RNIB, and our own head-scratching:
- Effective personal guidance in a closed environment (like a guide dog but electronic)
- Obtaining layout and product information of unfamiliar environments
- Learning of a user's buying preferences
- Details of special offers
- Obtaining information on supermarket items immediately surrounding the user
- Efficient route planning to pick up all items quickly
- Visibility to surrounding people
- Location information

Effectively, "to enable a blind or visually-impaired person to shop completely independently". And I'm sure we can expand the idea to more than just shopping.