Academic essays, which may be called "papers", are usually more formal than literary ones. They may still allow the presentation of the writer's own views, but this is done in a logical and factual manner, with the use of the first person often discouraged. Longer academic essays (often with a word limit of between 2,000 and 5,000 words) are often more discursive. They sometimes begin with a short summary analysis of what has previously been written on a topic, which is often called a literature review.