Billy's question, " I was hoping to find an explanation for how they couldn't see the particles and what direction they went, yet they knew that there was a random chaotic pattern? How did they "know" without seeing? "
The easiest way to explain is the video animation, if it's observed then whatever object they are firing them at leaves a mark. I 'think' the observation recorded is the path itself, if it's fired straight and it's observed and recorded the whole path is in a straight line and the board or target shows where they struck. If the path is not being observed then the target board shows it's being stuck in many other areas like the wave pattern.