For a 16 marker, the examiner will expect to mark about 6 of those marks for the theory behind and argument, and 10 of these marks for the evaluation. Therefore, you should expect that over half of your essay should consist of evaluating the studies/research/theories It's important that you start your essay with a strong introduction; informing the examiner exactly what you will be arguing and this argument should follow through all the way into the conclusion. Having said this, just because you need to make your argument clear it does not mean you can ignore the other side of the argument, for a comprehensive evaluation both sides need to be considered. A good method to do this is PEE: point, explanation and evaluation. Make the examiner understand the point you will be making in this paragraph, introduce the theory behind it and the studies. Explain what these studies mea for your point. Then evaluate the studies based on validity, reliability, their samples and other biases etc. Ensure that every evaluation point is linked back to the question and to your argument.