I had been to one of the State Bank of India ATMs in Bangalore to withdraw some money. I keyed in an incorrect PIN out of curiousity to check what happens. Alas! It displayed the Select Transaction page with options like Balance Enquiry, Deposit, Withdrawal etc. Was I logged in successfully with an incorrect PIN? Not really. When I randomly selected the Withdrawal option, the ATM prompted a message that I had entered an incorrect PIN and expected me to enter correct PIN to proceed with my transactions. Why did the software wait for me to select a transaction and then prompt me that the PIN was incorrect. Isn't this a serious usability issue? Isn't the end user(in this case, me) tricked that he/she is already logged into the system.
In the above scenario, ideally if the PIN was incorrect, an error message should have been displayed almost immediately after the validation instead of displaying the Transaction page, letting the user select any transaction and then prompt the message.
Next time you key in an incorrect PIN at an ATM, watch out!
Pari - http://curioustester.blogspot.com