Maggie's right ,
3nodding The main thing about pendulums is that they're affected by your will, let's say. Like Maggie said if you think about one of the answers, or have high hopes for the answer you want, the pendulum will reflect that. I was told that the best way to get a correct answer is to clear your mind. By just focusing on the question, I think there was supposed to be a higher chance of getting the answer to the question.......
Wait, here...
"....The pendulum, as an extension of the person using it, may be influenced both consciously and subconsciously making the responses inaccurate. Wishful thinking or a preconceived outcome, however slight, can be magnified making the use of the pendulum in that instance ineffective. One must take steps to prevent this. Insufficiently specific questioning can result in senseless responses...."
I think All I'm managing to do is just repeat what was already said..... There were also ways to hold the pendulum and stuff like that. If you want to find some more You can google it ( though, I think you should go with what Maggie wrote. It's alot simpler and easier to understand.)
Here's a site I found a while ago... I think it was an OK site, though it kind of repeats things.....
http://emeraldinnovations.co.uk/radionic/Pendulums/How_to/how_to.html