User error

common errors to plan for

[willybfriendly]

It never ceases to amaze me how people can come up with creative ways to ferret out all of the assumptions we make when designing a program. I don't mean hackers, but rather the mass of computer illiterates that populate the Internet.

We all know how to protect against the most basic errors, e.g. bad email addresses, bad URL's and such, that are entered into a form. We all know how to let people retrieve a password that they have forgotten. But...

I would find it helpful if all the gurus out there would share their wisdom regarding

1. How do you challenge your own assumptions when designing in order to foresee and avoid end user error?

2. What are the most common end user errors you have encountered, and how did you write your code to frustrate the illiterates out there?

WBF

[jeremy goodrich]

Most of the time it's with form input that has 'gone missing' or that the user over looked for my sites.

I just trap the error, and reprint the data with a user friendly (big letters) message that points to the missing bit of data.

Other than that, double checking the data against a db, if necessary, also string conversion to lower case first to make it match up perfectly.

[BCMG_Scott]

When I code I try to think of every conceivable value that I could put into a field. Sometimes I just randomly type stuff. Make sure you test the quotes, back tick, pipe, slashes and parenthesis - most of them have special meanings and can easily burn you. I test one field at a time initially, then test the form as a whole. Then, I find some guinea pigs (err I mean volunteers) and have them test it.

Some common problems I have run into are missing data (which is easy enough to check for). The most annoying one is dates. People type dates differently depending on their geographic location and schooling (e.g. Europeans will type a date dd Month yyyy, techies tend to go for yyyy-mm-dd or yyyy-mon-dd). Fortunately PHP does have a date string conversion function.

Scott Geiger

[lorax]

>> How do you challenge your own assumptions when designing in order to foresee and avoid end user error?

Assume the worst can happen and plan for it. If you need dates in yyyy-mm-dd format, assume they will be put in with mm dd, yy or mm/dd/yy ... and build error handler functions to handle the different possibilities.

>> What are the most common end user errors you have encountered

Mispellings and folks that don't like to read the help files/instructions. Which invariably leads me to developing apps that are as simple and easy to use as possible. If the right way to do something is also the easiest, you have a much better chance of the user doing what you expected.

[Sanenet]

Experience, planning, testing and a dark outlook on humanity :)

As far as dates go, I prefer to put them as three dropdowns, and just parse them into a database afterwards. Error check everything, and anything that is remotly difficult put some text explaining the input format for the user.