Determining the difference between Academy Award nominations for acting in a leading role versus a supporting role isn't always easy. It doesn't seem like a precise distinction can be made. Even within the range of supporting performances, there is a significant difference between the cameo and the roles typically occupied by character actors. At their best, though, even small contributions can make a huge impact on the story or other characters. This year, in fact, the Oscar that interested me most was Best Supporting Actress. I was not disappointed.