The American Psychological Association (APA) style is a set of rules or guidelines designed to ensure clarity and uniformity of scientific writing. This publication manual aims to minimize distraction and maximize precision in the writing process. The guide also standardizes nearly every aspect of writing, such as: authorship; headings; bias-free language; punctuation; abbreviations; constructing tables; avoiding plagiarism; and citing references. The APA documentation style is used for research in science-related fields, whereas the MLA is utilized for research in the liberal arts. There are thousands of peer-reviewed journals, references, and books that use APA as their style guide. APA also provides a format for cross-referencing sources, from citations-in-text to the reference page. Cross-referencing is of great value to researchers who need to locate original sources for their own research projects. Careful use of APA adds credibility to the writer by drawing upon the authority of the source material. Proper citation of sources in APA can also help the author avoid charges of plagiarism, which is a very serious offense. APA has been criticized for being choppy and very difficult to master. The 6th edition of APA style has improved significantly from the 5th edition, with simplified heading levels, abstract with key words underneath, author note, seriation for organization of material, and no retrieval dates for citations. The reference page also contains "DOI" designates. The 6th edition is much sleeker in appearance than the cumbersome 5th edition. A huge challenge in the new 6th edition is creating a unique header on the title page. The 6th edition does not allow the words "running head" in headers from page 2 onward. Another area of confusion and novelty is the use of "DOI" designates for journal articles and some scholarly books in the reference section of the paper. Digital object identifiers (DOI) are unique strings of numbers and letters to identify scholarly content in the online environment. Clicking on the DOI that accompanies a citation furnishes the original online journal abstract. The DOI for content material is created and assigned by the publisher. A user-friendly free DOI lookup is provided by crossref.Org. Here are some resources on APA style that I have found to be of inestimable help over the years: General apa guidelines - purdue online writing lab Sample apa paper Sample Paper: One-Experiment Paper Sample two-experiment paper Sample meta-analysis paper Citing sources using apa manual (6th ED.) Citing legal materials in apa style