I recently got back from collecting data in Russia. This particular study brought into focus for me the issues involved in making experimental data public. In this study, I videotape people as they listen to stories, look at pictures, and answer questions about the stories. The videotape is key, since what I'm actually analyzing is the participants' eye-gaze direction during different parts of the stories (this can be used to partially determine what the participants were thinking at different points in time).
Sharing raw data would mean sharing the videos...which I can't do. These videos are confidential, and there's no easy way of making them anonymous, since they are close-up videos of people's faces. I could ask participants to sign a waver allowing me to put up their videos on the Internet, but I suspect most of my participants would just refuse to participate. Many were concerned enough about the video as was.
Now, I could share the semi-processed data -- that is, not the videos themselves but the information gleaned from them. I already discussed some of the problems with that, namely that getting the data into a format that's easy for someone else to analyze is extremely time-consuming.
This isn't an issue with just one study -- more than half the studies I run are eye-tracking studies. Many of the rest are EEG studies, which can have several gigabytes of data each and thus it's simply impractical to share the data (plus, when dealing with brain data anonymity is even more a concern). I do some kid studies where I simply write down participants' responses, but if your goal was the check to make sure I'm recording my data correctly, that wouldn't help -- what you'd want are tapes of the experiments, but good luck convincing the ethics board to allow me to post videos of young children participants in experiments on the Internet.
[Those are my laboratory studies. Data from my Web-based studies is actually relatively easy to share -- though you'd have to be proficient in ActionScript to understand it.]
Certainly, there are many behavioral researchers that wouldn't have this problem. But there are many who would. Mandating that everyone make their data publicly available would mean that many kinds of experiments simply couldn't be done anymore.
3 hours ago in The Phytophactor