This advice is very dear to my heart, for as an editor I find myself suggesting it to nearly every writer I meet. It is age-old wisdom, handed down from teacher to student since the dawn of time (or thereabouts).
“Show, don’t tell.”
The essence of this advice is that, wherever possible, you should focus on creating illuminating description (show) rather than flat-out explaining things (tell). The main reason behind it is that it helps the writer to engage with the story in such a way that encourages realistic moments and characters and a consistent perspective; these cradle the reader inside the story world so that they feel like an essential part of it—almost as if they are living the story.
“Tell” can occur through use of a single word or a series of sentences.
Many students are required to purchase—and perhaps even read—an invaluable writer’s tool known as Strunk and White’s “The Elements of Style.” Possibly the most important of the 22 rules that make up the first half of this wonderful guide is number 17, which simply states, “Omit needless words.”
I think there are two primary reasons why so many students tend to go overboard with unnecessary words in their papers: They haven’t done the research and are trying to hide the fact by over-writing; or they think that the paper will sound more scholarly if it is filled with obscure, big, or a high volume of words. To the former group, a tip: Your professor is reading for content and will notice if you don’t know the material. To the latter group: If you know your topic, you’ll sound far more scholarly by discussing it simply and accurately—don’t force your reader to dig out a dictionary.