That's my point. You can't really know if they are correct. You just guess, if the notes are fit or not to the song. We could argue that what really tests is the listeners ability to recognize dissonant notes if all songs in the test don't have dissonant notes in them. But then its not a pitch sense test. There was one other test that I took that I see more accurate than this one: http://tonometric.com/adaptivepitch/ This one measures how little a difference of pitch can you note. It starts with a difference of 12hz, and ask you to tell if the second tone is lower or higher in frequency than the first. When you have answered a few of them correctly, it reduces the difference of pitch. I remember I was able to recognize differences of 0.75Hz before I started to fail to answer correctly.