I'm building a classifier of multi-class problem. In my context I have to classify vehicles into five categories: cars, vans, trucks, buses and motorcycles. I would like to use some measure to represent the classification performance for each class and for all of them. In the samples I have the motorcycles are few meanwhile there are a lot of cars so the classes are clearly unbalanced. I read that the Matthews correlation coefficient (MCC) is better in this case but I didn't find any reference that confirm this.
Please, could you help me on this I'm a little bit lost and I don't know which measure to use.