Premise

This is actually a pretty common question among students, as it’s often unclear why we’re told to cite sources within a particular style. Basically, the reason is that different citation styles serve to identify different elements of information as valued from sources within a particular field.

This is exactly why for some assignments, and in some classes, teachers and professors will adamantly tell you to use one citation style rather than another. So which ones are used with which effects in mind?

Examples

Just look at the difference between two citations from perhaps the two most common citation styles: MLA (Modern Language Association) and APA (American Phycological Association):

• MLA: In the Victorian England, most working class clowns were actually considered to be highly respected members of society (Sanders 21).
• APA: In the Victorian England, most working class clowns were actually considered to be highly respected members of society (Sanders, 2014).

The difference here might not seem like much, but the minor details are actually really important. The MLA version includes the author’s last name and then the number “21,” which indicates the page number from that source. Any reader who knows MLA and expects your work to be in that format, will see this number “21” and know, “If I want to go find that direct quote—and more information about it—I can look at the Works Cited, find that source, and scroll to page 21 of that text.”

Contrastingly, the APA version includes the author’s last name and then the number “2014,” which indicates the year in which that source was published. The distinction gets to the core of why certain instructors (and publications within certain fields) use one format over the other. In APA, this publication year is given rather than page number, because typically, scholars, experts, and other professionals within the fields of those who will read your work value referential, in-text identification about when the source was published. You see this style among many research publications, for example, which makes sense if you consider that researchers should presumably often be concerned with the relevancy of when other research was published in context to other such findings cited within a work and more broadly.

APA citations sometimes include page numbers too. But again, the value here for readers of this format is knowing when different sources were published.

There are plenty of other citation styles that optimize other information (like footnotes, endnotes, etc.), which as mentioned above, largely dictate why different fields prescribe some formats over others.

Further Considerations

• If you’re not sure what citation style to use (or why) ask your instructor, boss, supervisor, or anyone else in charge of prescribing whatever format you’ve been told to use.
• Looking up samples of similar documents can be a great way to decide what citation style might work best for your work in cases where you’re not provided with specific examples or guidance.
• Keep in mind that each citation style has a ton more rules, guidelines, exceptions, and specific quirks. There are plenty of situations that fall outside the examples above that can impact how and why certain citation styles prescribe certain specific conventions. So when in doubt, you need to make sure that you review all of that specific style’s rules.