APA style -- created by the American Psychological Association and used by many colleges, institutes and publications -- requires certain types and sizes of paragraph indentations. In the body of an APA paper, the first line of each paragraph must begin one half inch away from the left margin, and the following lines must begin flush against the margin. In the reference list, the format reverses: The first line starts at the margin, and subsequent lines are indented half an inch. To apply these rules in Microsoft Word 2007 or 2010, use the Paragraph dialog box.
Body of the Paper
Select all the text in the body of the paper, if you already wrote it. If you're beginning the paper, simply click where you want to begin indenting.
Click the "Home" tab on the Ribbon.
Open the Paragraph dialog box by clicking the diagonal arrow, pointing downward and to the left, in the left lower corner of the Paragraph group on the Ribbon.
Click the "Indents and Spacing" tab at the top of the dialog box.
Click the field labeled "Special"; on the drop-down menu, click "First line." Word will automatically set the indentation size to half an inch, which is the correct size for APA format.
Click "OK" at the bottom of the dialog box.
Select all the citations, if you already wrote them, or click where you plan to begin writing the citations.
Open the Paragraph dialog box again.
Click the "Special" field again; this time, select "Hanging" from the drop-down menu. Word will automatically set the indentation size to half an inch, which is the correct size for APA format.
Don't include the title page, primary or secondary headings, or the title of the reference list when you select text. These elements of the paper don't need any indentation. Even when you center a title or heading, the centering should place the title squarely between the left and right margins; if you indent the line, that will move the "center" farther to the right of the page.