Analysis of research aims and suitability of experiment design employed. Not all experiment designs are suited to every piece of research, although for many experimental situations multiple designs can be considered. Your task is to not only assess suitability, but to consider whether alternative designs may have allowed stronger conclusions to be drawn from the research.
Analysis of statistical methodology. Different statistical tools are used for different experiment designs. Your task is to determine whether the tools applied in the research have been appropriate to the situation or whether alternatives could or should have been employed. Where parametric tests have been used, determine whether the assumptions on which they are built have been properly addressed in the journal article.
Quality and structure of report. Put yourself in the position of an employee in industry or research when writing this report. Your boss would be looking for a well-formatted and structured report, one where it is easy to extract information and analysis from. Make sure you report is sectioned properly; at a minimum you will include an introduction, experiment design, statistical analysis and conclusion sections.