Details of marking scheme for question 2(b) on Test 2:


0 - if you said nothing, circled points but didn't say why or what you 
were circling, if everything you said was completely irrelevant.

0.5 - if you said something with respect to outliers but really said 
nothing else, or something with similar regards, oh and if you said 
there was a lot of variability as seen in the residual plots

1.0 - if you said the above plus more such as discussing influential 
points, and what that might suugest about the model, if they talked 
about "variability" and actually gave some reasoning

1.5 - the above plus some discussion about the model and the data - 
i.e. what this meant about the approriateness of the linear model

2.0 - you pretty much got it - you mentioned something with regards 
to an appropriate range of the data that the model may only be suitable for

Also, some people wrote a lot in terms of general information i.e. what 
information  you can get from the plots given but never actually said 
anything about the plots given! So, if they had written all of that 
with respect to the data they would have received more marks.