I sometimes joke about the concept of Death Of The Author (DOTA, for the duration of this post), just like I joke about Linguistic Descriptivism (or LD, for the duration of this post).
You see, people use DOTA to mean all kinds of things. People also use LD to mean all kinds of things, and they often use LD and DOTA in a rather self-serving way. If I tell you to speak clearly and plainly, and to use and interpret words with charity and parsimony, and to stick with your own definitions, you may tell me that this is just how people speak. At the same time, many people make prescriptions about language, and they justify their prescriptivism with "language evolves". You can't have it both ways!
With DOTA, the situation is a bit different. You usually don't know what it means, or at least you don't know what a particular instance of the phrase DOTA mean in context. Or, to use linguistic jargon, there is a difference in meaning between the original DOTA essay, the common usage of DOTA, and any particular utterance containing the phrase "Death Of The Author".
It is my contention that even though you may think you understand what Barthes meant, most uses of DOTA are not actually based on the same meaning or definition as the one Barthes had in mind, or the same that a Barthes scholar would have in mind. Furthermore, I do not think that even people who have read Barthes (whether recently or some time ago) are using the phrase or concept of DOTA in the same way. Sure, they are using DOTA in the "correct" way when they talk about Barthes, but they do not use it the same way (not even the same "incorrect" way), when talking about other authors.
I do not think it matters whether someone read Barthes, and I do not think using DOTA "wrong" means that somebody hasn't read the original text, or doesn't know the correct meaning. The meaning of words is not defined by fixed dictionary definitions, after all, but by common usage. When a Tumblr user with a name based on the classic pet-animal + gender + sex-organ + number url name (e.g. elephanttwinkuterus420) invokes DOTA, it could mean any of the following:
Miku Wrote Minecraft: Notch didn't write Minecraft. Virtual computer voice girl character Hatsune Miku wrote Minecraft. When talking about Minecraft, you should do all your analysis based on the assumption that Miku is the author of Minecraft.
Fuck Canon: When analysing a work, the "author" has no weight. Who is to say what happened in The Lord of the Rings? One dead guy or tens of thousands of fan fiction authors?
Author as Body of Work/Author Through Works Alone: You shouldn't think about Stephen King as a guy who lives in Maine next to a lake and writes ten thousand words per day. You should think about Stephen King as the author of many many many books, and many stories about a main character who lives by a lake in Maine. Those are not the same! We know much more about the life and opinions of Stephen King than about William Shakespeare, but we know what matters about Shakespeare: His writing.
Author as Abstraction/Virtual Image/Function/Implied Author: You need an author. You can't just read a book as if it wasn't written intentionally. If the book says "the curtains were blue", that's not just information. I mean, it means the curtains were blue, but it was put in there by somebody. A book isn't like satellite data. The words in the book were curated. Of course you don't need to know anything about the real human person who wrote the book, but you have to assume that there is authorial intent. Movies aren't documentaries about parallel worlds.
God Is Dead: No more WordOfGod. If the author says "the curtains were blue" at a Q&A panel, that doesn't matter. It only matters if he wrote it in the book. If the book just describes the curtains as "soft velvet", then you may imagine them as red. No tweets, supplementary material, or pottermore post can change what is written in the book. The manual of the official video game adaptation is on thin ice.
Of course, what the author says he meant to say is also irrelevant.
Death of The Auteur: We should embrace modern media like movies and video games not as art, but as products, as design by committee, without unitary vision. We should not read books as expressions of the personality of the author, either. A book can be written in a certain style, but that doesn't say any thing about the author as a person. The style is a style, not the author's style.
You should not assume that the author wanted to express himself, either. You should not attribute the "message" of a movie to its director.
Reader Response Theory: The meaning of a text is what you take away from it, not more, not less. The author doesn't figure into it.
No Invalid Readings: As a result of the above, there is no such thing as an invalid reading. If you read it that way, and you did so in good faith, there must be support in the text for your reading. Nobody can argue against your reading, only for their own reading. No reading is ever "correct", because no reading can be more correct than any other.
No Unintended Readings: Actually, this expands to the "intended reading". There is no such thing as "the" intended reading. There is no such thing as "the" authorial intent. Every reading isn't just equally valid, every reading must also be equally intended by the author (function, not person).
Trust The Process: There is a method or set of methods to determine the "true" meaning of a text, and following the method leads to the truth. In this view, using the correct method will not just lead to a valid interpretation of the work, but to the correct interpretation. This method knows the text better than the author himself.
Death of the Abstraction: When reading, interpreting, or analysing, there is not even such a thing as an author function. You should not think about authorial intent when you read a text, or a body of work. There is no intended meaning. When the narrator turns out to be unreliable, then that's just the kind of guy he is. There is no authorial intent behind the narrator. Movies are documentaries about parallel worlds.
Psychoanalysis: There is a method or set of methods to determine the "true" authorial intention, based on the text, whether or not the author (person) believes this, whether or not the author (person) has explained the work. The mental state of the author in unconscious and not directly accessible to the author when he's giving an interview, but it is accessible indirectly, from the text.
The End of History: When reading, interpreting, or analysing an old text, the last thing you should do is pick up a history book or the author's biography. Books by dead authors should be read through a presentist lens, and everybody who talks about "historical context", the "political situation", "cultural differences", "references the audience back then would surely have caught", or "Straussian hermeneutics" should be beaten with Roland Barthes's essay, carved into stone tablets. Cool. Now go ahead and read Moby Dick, Bleak House, and Ulysses.
Only Watsonian Readings: When reading, interpreting, or analysing anything, you must never make a Doylist statement, assumption, or inference. You can never say "they fell short of their goals", or "a better writer could have pulled it off ", or "the play drags here, probably just to pad out the second act and to make it as long as the first", or "the production budget probably didn't allow for an exterior shot of the mansion". There can be no mistakes, no aspirations, no intentions, that are visible to Doyle but no Watson. If the special effects are bad, that's just what the lasers and explosions look like. There can still be an intended meaning, but there cannot be a real-world explanation.
Death of the Critic: Let go of the bourgeois idea that the job of the author is to be cryptic, and the job of the critic is to explain what the author means. Just read the book without worrying what it should mean, what these symbols are. Don't let critics gatekeep meaning! If you read the book yourself, and think for yourself, that's still better than having access to the "true" intended meaning, because the price you pay is having somebody else do your thinking for you.
Death of the Audience: Honestly, this one is a toughie. The phrase Death of the Audience is so catchy, and many people have arrived at it independently.
As a writer, you shouldn't think about your target audience, or the intended audience, and how they would interpret your text. You should write for yourself, or people like yourself.
As a reader or critic, you shouldn't think about the intended audience. You can just draw your own conclusions, without having to think about what the author thought what his intended audience would think.
As a reader or moviegoer, you shouldn't base your own opinion on the audience consensus on goodreads or critical reaction on rotten tomatoes.
Weekend at Bernies of the Author: We will ignore extra-textual statements by the author when it comes to the meaning of the text, but we will use the text to make inferences about the author as a person.