A thesis statement is a document that outlines a proposed thesis in an area of study. These will range in length and style depending on the subject and the stage of study. A scientific thesis statement is more likely to contain examples of statistical data and a proposed series of experiments, while a humanities statement will focus on the key arguments of the work. The majority of thesis statements have the purpose of clearly setting forth a proposal for an extended piece of work, giving examples of how the argument will be developed, and how the final piece of work might be structured and presented. This might include potential chapter headings and any preliminary topics that the student feels will be covered in depth, as well as some references intended as a rough summation of the research to be covered. An undergraduate thesis statement, traditionally written in the final year of study, although it may be written in some cases at the end of the second year, is typically 500-1000 words in length. At postgraduate level this will increase exponentially depending on the length of the work, and is expected to be more detailed and wide-ranging in its presentation.