The pendulum can only give clear and accurate answers if you become a clear channel for it, you need to be grounded and centred and in an almost meditative state IMHO otherwise your conscious mind can infuence the answers making what you want to hear become the answer provided or what you fear will be the answer turn up. There are several schools of though on where the pendulum gets its information from, I believe that the answers come from connecting with the universal energy that is all around us and if you are open and clear minded then you will get the right answers, it is always easier to dowse for information that does not affect you personally in a highly emotive way.