If you are assigned to play the 'audience' role for a given class session, then you will be required to submit a brief written critical evaluation, so called critique, of each of the readings that we are to discuss in class that day. Critiques are a short (typically two pages long) writeup of the day's reading, which will be due at the start of the class.
In general, I would advise you to pose yourself concrete questions (in fact, state those explicitly in your written document) that you then proceed to answer in your critique related to the reading in order to help you organize your thoughts and thus writing. The hardest part of writing a good critique is probably for you to figure out what are good questions to ask yourself about the reading, then to explicitly formulate those questions. Once that is accomplished, you can proceed to answer them one by one. Examples of such questions may be : (a) what are the main features of stream applications that these proposed techniques seem to service, (b) what are hidden or stated assumptions about the stream applications that the paper makes, (c) what are key differences between this new result and the existing relational database technology, and so on.
So first and foremost the critiques are for you, namely, for you to prepare yourself for class discussions.
Hence, reading and discussing of the assigned papers with your student colleagues before class is highly encouraged, and it should certainly help you to prepare your critique.
When you study the assigned reading, make a list of the points you find particularly confusing, ambiguous, interesting, controversial, etc., and make sure to bring those up in class. Hopefully, others in the class in particular the proponent and the rebuttal team members will be ready to answer those questions.
In general, I will ask you for your input on these points you wrote down so that you can discuss them in class. Thus your critique and more should be in your "head", as well as in paper on front of you when you arrive in class.
The grading scale will be:
No late critiques will be accepted - as we will be discussing the material in class that very day. Also, do see the note on plagerism, and refrain from for example copying the abstract or summary from the paper directly into your critique word for word.
Note: If you are a proponent or rebuttal team member for that day, then you do not need to submit a critique of the papers you are in charge of. Instead you will be preparing much more detailed material, namely, presentation slides and subsequent tutorials.