In 1929, a group of businesspeople and social scientists got together and came up with what is known as American Psychological Association (APA) Style. Their aim was not to give college student's fits; rather, they sought to codify scientific writing to make it easier to read and comprehend. A running header in APA Style identifies the title and page number of your paper throughout its entirety.
APA Paper Structure
Though best known as the primary way to cite research paper sources in the social and behavioral sciences, APA Style covers general essay structure extensively. In addition to requiring a running header, the APA format necessitates a title page, abstract, main body and reference list in your paper, although individual professors often tweak these requirements. Each section must follow stringent stylistic guidelines. You should include a running header on every page of your document. But the particulars on the title page differ from all other pages, which maintain consistency throughout.
The title page of your APA Style paper includes a running header that is distinct from the header that leads off all other pages. As illustrated at the Purdue University Online Writing Lab's (OWL) website, create a header on your title page. Inside of it, you type "Running head:" followed by the title of your paper in all capital letters and the page number. On the title page, use "1" as your page number. Locate the title flush left on your paper and the page number flush right. As for your title, it should be no more than 12 words long. Avoid pointless words and abbreviations. Take up no more than two lines of space with your paper's title.
Body of Paper
The running header throughout the remainder of your APA Style paper differs slightly from the title page. As Purdue's OWL notes, you simply remove the "Running head:" portion. Include the title of your paper in all capital letters flush left, along with the page number flush right.
Abstract and Reference List
If your professor requires an abstract between your title page and the main body of your paper, you must include a running header on it as well. The running header on your abstract page is formatted in the same way as in the paper's body. In almost all cases, you will use a reference list at the end of your essay. These pages also require use of a running header following the same format as in the main text.
Versus MLA Style
For comparison purposes, and because you might run into Modern Language Association (MLA) Style at some point in your college career, MLA requires a running header similar to APA Style. As outlined on Arizona State University's website, MLA format does not mandate a title page. Beginning on page one of your MLA Style paper, use a running header that includes your (the author's) last name and page. Locate this information at the edge of your paper's right-hand margin.