We filmed four different clips of two people waving in different directions each time so that when it was put together it would almost go in a sequence even though they were not directly waving at each other one clip was waving at the other etc. All the clips can be imported into premiere pro at the same time so that they are all there together.Drag each clip down onto the timeline one in each section (video1, video2..). Then make sure that all of the clips line up so cut any that are too long to the size of the shortest one as this is easier than trying to make any longer. To make sure that all the videos are the same scale as the project right click on each and click on scale to frame size. Go down the clips and as you click on them in effect controls at the top, under the motion tab it has a section that says scale, all of the clips will be scaled at 100% so to allow for the split screen re scale each clip to 53%. After this is done you still cannot see all of the clips as they are all scaled to the same size so they have to be moved in to the different sections of the screen. In order to do this again in eefect controls under motion there is another section that says position and to move the clips you need to drag the percentages either left or right and you will see the clip moving. Continue to move the percentages of both numbers shown until the clip is in the section of the screen you want it in. Do this to all four clips so that they are in the four different areas of the screen.