Human Error and the Design of Computer Systems<\/a> says:<\/p>\n“In 1988, the Soviet Union’s Phobos 1 satellite was lost
\non its way to Mars. Why? According to Science magazine, “not long
\nafter the launch, a ground controller omitted a single letter in
\na series of digital commands sent to the spacecraft. And by
\nmalignant bad luck, that omission caused the code to be
\nmistranslated in such a way as to trigger the test sequence” (the
\ntest sequence was stored in ROM, but was intended to be used only
\nduring checkout of the spacecraft while on the ground) [7].
\nPhobos went into a tumble from which it never recovered.
\n“<\/p>\n
Of course, it was dubbed as of ‘malignant bad
\nluck’ instead of ‘bad design’.<\/p>\n
Recognition rather than recall (severity = high)<\/h2>\n
Jakob Says:<\/b><\/p>\n
Make objects, actions, and options visible. The user should
\nnot have to remember information from one part of the dialogue to
\nanother. Instructions for use of the system should be visible or
\neasily retrievable whenever appropriate.<\/p>\n
What it means:<\/h4>\n
How do you open doors in your office campus? How many do you
\npush to open and how many do you pull to open? Can’t
\nremember? Doesn’t matter even I don’t know remember,
\nbut when you get to the door, if you know precisely what to do
\nthat means the door allows you to recognize what to do, to open.
\nAnd yea, next time keep an eye out for people who pull when they
\nhad to push or vice versa. Many doors have been broken because of
\nthat. Especially glass doors.<\/p>\n
You know it’s an error message the minute you see a
\n‘X’ encased in a red circle. It is a visual cue. The
\nred serves as a warning. You just know it the moment you see it
\nbecause you recognize it. I have come across software that
\ndon’t display this graphic.<\/p>\n
This is just one example; but a very important one. Imagine,
\nif you were prompted with an error message without the red circle
\nwith the ‘X’ in it? You’d click
\n‘Ok’ nine times out of ten. Phew! I did a short
\nsurvey on contingency design, I found that 6 out of ten users
\n(all software programmers ha!) never read the pop-up alerts. They
\njust clicked ‘Ok’.<\/p>\n
Help users recognize, diagnose, and recover from
\nerrors (severity =high)<\/h2>\n
Jakob says:<\/b><\/p>\n
“Error messages should be expressed in plain language
\n(no codes), precisely indicate the problem, and constructively
\nsuggest a solution.”<\/p>\n
<\/b><\/p>\nWhat it means:<\/h3>\n
‘Java null exception error’ freaks me out. Who is
\nnull? What is a Java? Let me get out of here before someone sees
\nme.<\/p>\n
That’s a layperson’s reaction to cryptic error
\nmessages. My word processor’s favorite is
\n‘Instruction at 000000×1 failed… dah dah dah’ I
\nhave been using it for five years now and I still don’t
\nknow what it means. But I used to lose data because of that all
\nright. A software is unsafe if it can’t tell the users what
\nwent wrong, what needs to be done.<\/p>\n
Visibility of system status<\/h2>\n
Jakob says:<\/b><\/p>\n
“The system should always keep users informed about what
\nis going on, through appropriate feedback within reasonable
\ntime.”<\/p>\n
What it means:<\/h3>\n
Remember? Those blue progress bars that tell you how much more
\nto go and how long, when you download stuff from the net? Those
\nmessages that say ‘your request is being processed please
\nwait’? That is telling the user what’s going on.<\/p>\n
I wanted to book a domain name, so I went to www.net4domains.com<\/a> I chose the
\nname I had wanted and I proceeded to payment. I gave my credit
\ncard details and hit the ‘Proceed to payment’ or some
\nother button meant for finishing the transaction. The first time
\nI hit it, nothing happened. So I hit it again. It worked. I was
\nso happy that I got my own domain. It lasted only till I saw my
\ncredit card statement. I was charged ‘TWICE’. Yea,
\nbecause I clicked twice. The transaction is in dispute now. What
\nif I was buying stocks or say, a costly book? I know I wont lose
\nmoney, but why take away my peace of mind?<\/p>\nSome sites tell the user ‘Hit only once’! but
\nthat’s too flimsy. I mean how can I book the same domain
\nname twice? Shouldn’t it ask me? In my case ideally the
\nsite should have told me ‘before hand’ ‘hit
\nonce and wait. Sometimes it takes a few moments to fire your
\nrequest’ Or some thing like that.<\/p>\n
Conclusion:<\/h2>\n
I am sure by now you know how ‘unsafe’ software
\ncan get to be. And hopefully, you’ll agree with me when I
\nsay, ‘software could ruin my life.’ Let’s hope
\nsoftware companies realize the potential threats and make
\nsoftware safer, taking a cue from the car manufacturers.<\/p>\n<\/p>\n