+**Our data set: Cochlear Implants**
+
+A cochlear implant is a small electronic device that is surgically
+implanted in the inner ear to give deaf people a sense of
+hearing. More than a quarter of a million people have them, but there
+is still no widely-accepted benchmark to measure their effectiveness.
+In order to establish a baseline for such a benchmark, our supervisor
+got teenagers with CIs to listen to audio files on their computer and
+report:
+
+1. the quietest sound they could hear
+2. the lowest and highest tones they could hear
+3. the narrowest range of frequencies they could discriminate
+
+To participate, subjects attended our laboratory and one of our lab
+techs played an audio sample, and recorded their data - when they
+first heard the sound, or first heard a difference in the sound. Each
+set of test results were written out to a text file, one set per file.
+Each participant has a unique subject ID, and a made-up subject name.
+Each experiment has a unique experiment ID. The experiment has
+collected 351 files so far.
+
+The data is a bit of a mess! There are inconsistent file names, there
+are extraneous "NOTES" files that we'd like to get rid of, and the
+data is spread across many directories. We are going to use shell
+commands to get this data into shape. By the end we would like to:
+
+1. Put all of the data into one directory called "alldata"
+
+2. Have all of the data files in there, and ensure that every file
+ has a ".txt" extension
+
+3. Get rid of the extraneous "NOTES" files
+
+If we can get through this example in the available time, we will move
+onto more advanced shell topics...
+