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Virtual Knock-out








Yesterday we started with de experiment. Our research plan was that we have three different games with each three different resolutions. Each subject plays three games at different resolutions and plays each resolution only one time. We decided this because this was the best way to avoid the decrease of concentration and the experience a subject builds up during the games. However, when we did four subjects, we found out that our research strategy not seems to work. It appears that there was a huge difference between the reaction time of the subjects, and because each subject plays only one resolution per game this wouldn’t work. If we had continued our research this way, we had unreliable results. The results would have been based on the persons and not on the resolutions. It would have been a good research plan if we had a few hundred people at least. Our new research strategy is to let each subject do three different games at two resolutions. So they play six games full. The advantage of this plan was that we can compare the reaction time for the two resolutions for each single person. Of course there are still three different resolutions so we make a scheme with randomize the movies and resolutions. We can’t play more movies per subject because of the decrease of concentration. We are hoping to get some clear en evident results with this new research method.Getting the subjects was also a challenge, because the most people we find do not want to spend half an hour time for us. At the end of the day we did 4 subjects according to the old research strategy and five subjects for the new one. It was a long and exhaustive day for all of us but we learned a lot. Today we continue the research this way. The lights had leaved now so hopefully the speed cam has still enough light to film. We use this speed cam moreover for synchronize the data. Filming the motion that happens on the screen with a normal camera would not work because the screen is showing us 24 fps and the camera is filming 24 fps, but these devices are not working exactly synchrony. With the speed cam we can see exactly when de subject is going to move when a frame disappears and thereby measure the reaction time and synchronies this data to the motion capture system.

Another day working on the Virtual Knockout project. Yesterday the focus was directed on preparing for the experiments, because the day after tomorrow they will take place. A few things needed to be arranged to make these preparations. For instance we started scouting for some volunteers who want to participate in the tests. Furthermore we tried some of the tests ourselves to determine the time spent with each participant. This for planning everyone in a schedule to prevent them from coming all at the same time. It was also to check if we had chosen the right order of procedures that we wrote down in a protocol and if there was something missing from it. We found out that it would probably take about 20 minutes for each person to get instructions, getting put on the markers for the motion tracking and doing the actual tests. That means it will a least take us a whole day to obtain enough data.

A lot of problems have been encountered and solved thus far, but yesterday we walked into a major issue. Last time we already found it, but at at the end of the day so we didn’t had any time to look into it. To synchronize both the data from the videos and those coming from the experiments we wanted to use a normal video (HD quality) which shows each test from every person. With the help of this video we thought we could bring the motion track data from the prerecorded videos and from the experiments in sync. The normal video unfortunately has a delay causing to run a few frames behind the motion track data. The video is still usable as an extra tool to see what movement has been made if it’s not clear from the motion track data alone. The synchronisation might still work with the video if we are able to exactly determine how many frames it’s running behind. The amount of frames can than be calculated into fractions of seconds with the known framerate in which the video has been shot. The question that arises here is will the accuracy of the test be compromised or not. The problem is that we cannot think about this too long, because of the deadline before which the experiments have to be finished. This is upcoming thursday around 19:00. The deadline is caused by equipment that is borrowed and need to be given back by the next day. If decided that the video isn’t suitable for the synchronisation part we have to come up with another solution after doing the experiments.

Today we will check the last videos that are converted into playable movies for the 4k display. After that, it’s finishing the last preparations for the experiments so the next day we can keep on going without any delay.


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