A trigger object can be anything from balls, a bunch of keys, a child's toy, or a marble. The idea is to leave these objects in a haunted location during an investigation in the hope that they might be moved through paranormal means.

In order to obtain quantitative data using a trigger object, you'll need to be able to measure any movement of the object. This can be done by placing the object on a sheet of paper and drawing around it. It's then easy to see if the object has moved. It may also be a good idea to point a static camera at the object in the hope of capturing the movement in a video.

You should always make sure that trigger objects are placed on solid, flat surfaces, ideally in a location where people won't need to walk past them, as the weight of passing footsteps might produce vibrations...