There's a scene in Penny Marshall's 1988 film Big where Robert Loggia's character (the owner of a toy company) is drawing a distinction between the content of a marketing report and the activity that takes place inside a large toy store on the weekend. The aforementioned distinction is addressed to Tom Hanks' character, (a twelve-year old boy who after making a wish at a carnival, undergoes a Kafkaesque metamorphosis into a thirty year-old man), who with ingenuous befuddlement replies: "What's a marketing report?"
Whatever a marketing report is, a safe assumption to make is that it will both look and read much differently than a Batman comic.
A marketing report belongs to one kind of genre. A Batman comic belongs to a different kind genre.
A marketing report is intended for one kind of discourse community. A Batman comic is intended for a different kind of discourse community.
Presumably, it would be a mistake for an employee of a large toy company or any large company for that matter (except maybe if the employee works for Disney or Time Warner) to produce a marketing report with a series of highly decorated square panels and speech bubbles.
Conceding my ignorance on the matter, I would hazard a guess that, unlike a Batman comic, a marketing report does not contain a plot or bother to develop either a protagonist or an antagonist, unless the antagonists are defined as being the other companies that hold greater market share. Likewise, a Batman comic will rarely delve into issues of market saturation or how the internet is changing the 6-12 age demographic in regard to action figures, which are not tied directly to a TV show or a film.
Of course, other genres exist besides marketing reports and Batman comics. I found this out the hard way when I began working at the writing center. Instead of a market report, I was instructed to compose a memo. Whatever a memo was, I knew it was different than a Socratic Dialogue; I knew it was different than a biography on John Milton. I just didn't know in what specific ways it was different.
Lucky for me, the Directors of the EIU writing center prepared for the unsophisticated consultant. I don't remember if I asked the Assistant Director for a sample of an ideal memo, or if she anticipated that someone would ask, and thus made the asking moot. However it happened, the director informed the class that three sample memos from bygone years were available for our perusal. The first chance I got I seized the folder and began to peruse, but only after whispering a sigh of relief. Ahh.
I supposed I could have guessed. I wasn't completely ignorant. Like I say, I had a pretty good idea of what a memo was not. I have written a lot of papers, for a lot of different classes, at a lot of different institutions, under the guidance of a lot of different professors, and not once had any of them referred to any assignment as a "memo."
Still, guessing is a risky epistemic strategy. Probably a better strategy is to provide an unsophisticated student, who is being introduced to a unfamiliar genre, with an ideal example. In this way, the student can get a sense of the specific differences that delimit the unfamiliar genre with the genres he is already familiar with.
Unlike Batman comics and marketing reports, genre differences can be more subtle. The more subtle the difference, the more likely a student is to transgress a generic boundary. For example, I learned two rules in my first composition course that did not hold in other courses.
First, I learned that when writing an essay, the conclusion should not include the phrase "In conclusion..." A few months later, I took a speech class. My peroration was marked down because I omitted the phrase "In conclusion..." Ouch, that one stung. My indignant diatribe did nothing except make me thirsty.
Second, I learned that when writing an essay, one should never use the first person singular "I." One should instead use the term "the reader." Fast-forward a few semesters, and I am sitting across from one of my many philosophy professors, when he asks me: "Why don't you use "I" in your papers? It is so much easier to read and more natural."
Avail yourselves of my foolishness. Do not presume that every paper you write will be in the same genre. Do not presume that every paper you write will be directed to the same discourse community.