File talk:Methgraph.PNG

Validity/Clarity of plot

 * The lack of units on the y-axis or label on the x-axis is bothersome.
 * The lack of an explanation for the scope or methods of the study used to collect the data makes the plot misleading. In particular, without knowing how many students were involved in the study each year it's unfair to plot the data on the same graph without error bars.

Source?
What is the source of this data? Don't say "the University of Michigan!" TomTheHand 21:05, 1 October 2007 (UTC)