After deciding the topic of review we have to go through the classic papers or research work related to that topic and its critics. We have to discuss the methods, aspect under study, study region, data used and conclusion. We have to compare the work of experts. We also analyse the approach or we can say view of various experts while studying that topic. We also analyze the appropriateness or lacuna's of the methods use. While reviewing the past study we can go by chronological order or according to sub theme. We also have to consider the contemporary study, trends etc.