Error detection in Web forms
Can you quickly spot the typo between a form field value ”+2731284325” and ”+2731294325”?
Now what if the form field had a cue? For example a colour cue on the border colour:
16 Colours provide instant visual feedback that there is a difference between the two form fields. That’s a 4 bit Web form error detection using md5.
When you enter the same data again and again in form fields like your:
* username
* email
* birth date
* credit card number
Each one of these “datums” could be associated with a cue. So you would subconsciously over time recognise you entered your details correctly.
This cue idea is useful for accessibility. People who are prone to making typos could use a cue (an additional band/channel) to quickly find mistakes.
I initially thought of form error detection, checksums & cues when I accidentally mistyped a number from a business card three times into my mobile. If that business card had a “checksum”, with the number (for e.g.) underlined with the according md5 colour chances are I would have entered that number in correctly first time into my addressbook. Saved the cost of the misdirected texts and saved an awful lot of time.
So a cue is especially applicable in mobile environs. Anywhere I imagine were copy&paste is not easy to do.
Of course a cue does not have to be a colour cue checksum. A ‘cue’ could be some other easily recognisable symbol like Wingdings, different CSS styling like border styles, Unicode symbols, playing card symbols and so on.
So I encourage you to please try my initial implementation called “Get a cue” with Web form input elements. For the developers amongst you, please look at the BSD licensed code. Feedback and patches are very welcome.
Hopefully a defacto ‘cue’ error detection algorithm rises to the top that will help everyone improve their input quality.
> get a cue <
sounds like lotus notes password field 
http://homepage.mac.com/bradster/iarchitect/lotus.htm#LOTUS12
but I like it, I’m just not sure how user will understand it I was quite confuse at first. And I’m not sure one need a full fledged md5 implementation for that but I might have missed something.
Hey Antoine,
You are quite right. It doesn’t have to be md5, it can be much simpler like just a sum. I hope to collect several “bookmarklets” and see which one is best.
Try write one.
Of course collisions with 4 bit checksums are very possible.
md5sum is a 128 bit checksum and it’s very hard to get a collision. “get a cue” uses just the first 4 bits of md5sum.
there must be some intersection where this checksum catches most errors. ‘Cue’ is not about being “fool proof” (thanks Jamie), or providing secure authentication.
I think you could fairly compactly represent 128bit with CSS, colours & Unicode. Though I think a much lower bit size, like 10bit can suffice for small input fields commonly found in Web forms.