Which one doesn't belong?

I recently came across Mary Bourassa and her blog can be found here.  She has a wicked post on "Which graph doesn't belong?"  I adapted a lesson, using her graphs, and then creating my own for a Math 30-2 class.  Here is my lesson plan for doing a "Which doesn't belong?" for Mary's graphs.  Of course this could change for the grade level and what is given.

1. Review the terminology we have used in describing graphs.  Such as relative maximums, minimums, asymptotes, non differentiable points, etc.
2. Pair students and provide each pair with the 4 graphs.  Ask which one doesn’t belong?
3. After some time, ask students to just raise their hands on who said Graph A, B, C, or D.  Do not ask for reasons.
4. Ask each pair to come up with a reason for why each graph does not belong.
5. Ask various pairs to describe why each graph does not belong.
6. Provide each pair with chart papers and ask them to draw to 4 different graphs where someone could answer the question “Which one does not belong?”
1. Ask students for criteria on making a WODB?
1. Some ideas are that each would have an equal chance of being selected.
2. There is something different about each graph.
3. Uses aspects of graphing that we have taught.
7. Trade sheets with other groups and have the pairs now create answers as to why each new graph does not belong with the other 3

Here the graphs right from Mary's site which would work well for a calculus class.

Here are some graphs for a Math 30-2 class.