I find few instances of academic writing in which “and/or” is a better choice than simply “or.” As the above image illustrates, when you connect a pair of words with “or,” you’re not ruling out the possibility of “and”; that is, “or” includes “and” within its meaning.
In my experience, many writers are using “and/or” in contexts in which it is unnecessary. For example, the research funding agency SSHRC includes the following sentence in one of their sets of application instructions:
- Other contributors include organizations (e.g., philanthropic foundations, private sector organizations) or individuals who are not invited partners, but who are likely to provide cash and/or in-kind contributions during the lifetime of your grant.
In this instance, “or” has the same meaning as “and/or,” but is less awkward. SSHRC could simply describe “cash or in-kind contributions.”
In contrast, consider a sentence like:
- Possible treatments include chemotherapy, radiation therapy, immunotherapy, and/or targeted therapy.
In this example, the use of the word “include” gives the reader the sense that an individual’s treatment or treatments could have any number of the options in that list. In this instance, “and” is the less awkward choice, but “or” wouldn’t necessarily be wrong, either.
Why is “and/or” awkward? Two reasons: one, no one uses “and/or” when speaking naturally. Of course “no one” is an exaggeration there—you might use it when speaking; you may have heard someone say it when chatting with you; it might have been your baby’s first pair of words. So, almost no one speaks like this. That’s a clue that the phrasing is awkward.
But the other reason I claim that “and/or” is awkward? Writers adopt it to sound formal, but in truth the phrase is rarely recommended in guidance for formal writing: various writers-on-writing have suggested that you should “never use this term” because it is “Janus-faced” with only an “ersatz air of authority.” “And/or” tricks you into thinking you’re being formal, when in truth you’re just sounding more awkward than is needed.
I’ve written elsewhere that it’s my belief that, too often, academics (like you!) are—implicitly or explicitly—led to believe that you should model their own writing on texts that are only average, rather than on examples of good writing. “And/or” is a case in point. You’ve seen it in lots of other peoples’ texts, so you think it’s a good idea to use. Lots of people are average writers. I want your writing to be above average.
What if I really, truly mean “and/or”? The phrase you’re looking for is “_____ or ____ or both.” Here’s the MLA style guide with an example for you.