Provoking spirits to cause them to make contact is something that unfortunately has become a common practice in the ghost hunting industry on television. When people see this happening, they think that doing the same will get more results. The only time that I feel it is appropriate to do so is if a homeowner is being troubled by a malicious entity, and the ghost has not made contact with investigators despite past attempts. Sometimes, the only way to deal with a bully spirit is to stand up to them. Unless an investigator faces this situation, I do not believe it is right to provoke a ghost. Not only out of respect, but also for safety reasons.
The most important reason that I do not provoke spirits is out of respect. Spirits are merely people without bodies. Though you may not be able to see them, souls still deserve to be treated with respect. Often the place where a spirit stays behind is one that they are attached to, or, they were afraid to move on, and the location gives them a sense of comfort. It is the same way that a place you and I consider to be home provides us with a sense of security.
Imagine if someone were to come knocking on your door. You answer, and a man that you have never met before inquires to ask you a few questions. This encounter with the stranger will go one of two ways; you may say yes, and proceed to answer the questions. After giving your answers, he leaves, and you finish what you had been doing before answering the door. The other option is that you politely say no, and ask him to go. But he does not, and instead, begins to ask more questions. Again, you say no. At this point you may be getting frustrated. He sees that being polite will not work with you. So he puts his foot in the doorway and edges himself inside. If you do not answer his questions, he will stay until you do. Now what you do?
Feeling threatened, you start to think of solutions. You can tell the visitor to leave, and if he does not, you will call the cops. You may force the door shut and lock it. Or, depending on what personality you have, you may throw a punch or two. Either way, you feel like your personal space is under threat. Provoking spirits is the same way. If they do not want to answer your questions, please do not force them to do so.
They may feel scared, and during that moment they may throw something at you, or try to hit you. Imagine yourself in the situation with the man asking questions at your door. If you feel that they will try and force their way into your home, you are going to stop them. Ghosts cannot call the police. They may ignore you, eventually give up and make contact, or get aggressive. Now, if they should get aggressive, which is rare, you cannot blame them for that. They are defending themselves just as you or I would do in the same situation.
If a spirit does not reply to your questions after a few attempts, the best thing do is leave. There is no reason to waste precious time when you could find evidence elsewhere. Either try another area of the location or call it a day. If you decide to leave, try going back to the site and ask different questions. Often results will not turn up until the second, third, or even fourth visit. So please ask yourself this before provoking a spirit: How would you feel if someone did the same to you?