piecemeal

When you do something piecemeal, you're doing it little by little, but in a seemingly random way, with no order or system.

Say you're a computer geek and someone calls you desperate to find out how to fix a computer that's just crashed. If you respond piecemeal to the caller's questions, she'll have to call you back many times to get all the information she needs to get the computer up again. You may like to talk to her, but she's not going to be impressed with your computer smarts.