Shamrock

I give two versions of a test to my statistics class and somewhere on the test it says to draw something next to their name so that I can tell what version of the test they had. So in March around St. Patrick's Day my statistics class took a test, so one version had to draw a pot of gold by their name; the other version had to draw a shamrock next to their name. Patrick told me that not everyone would know what a shamrock was, but I didn't believe him, I thought that everyone would know what a shamrock is. So as students turn in their tests, some of them had these rocks by their name with "shamrock?" written at the top. Once everyone turned in the test I asked one of them what a shamrock is and they didn't know, so we all got a good laugh out of it!