Once you have carried out a search, you need to screen your results for relevancy and then critically appraise and analyse the remaining articles.
Screening means analysing the results you find from your literature search to determine whether or not they answer the question or task your research topic has set:
You should only include results that meet your inclusion criteria: if something fails to meet any of the criteria, it should be excluded:
Identify the type of study you've found in order to select the appropriate critical appraisal tool.
Reading the abstracts should enable you to determine the type of study:
A number of checklists have been developed to help with the process of critically appraising articles from various types of studies. Here are some examples: