Annotations may be written with different goals in mind. There are three types of annotations, depending on what might be most important for your reader or according to your professor’s instructions. It is impossible to describe a standard procedure for all types of annotations because one annotation does not fit all purposes. In order to know the best type of annotation, it is prudent to consult your instructor or follow the instructions. For example, if the assignment states that your annotative bibliography should give evidence proving an analytical understanding of the sources you have used, then you are supposed to write an analytical annotated bibliography which includes evaluation of the sources you are using. The three types of annotated bibliographies are; summary annotations, critical annotations and a combination of the former two.