The authors consider four categories that affect our understanding of $hakespeare: the work, the word, the character, and the author. For each of these, they provide examples of ways in which the material multiplicity of the texts undermine what we think of as a unified whole.
As regards works, King Lear has not only multiple texts but multiple names; how do we identify it? Is it a history, a true chronicle, or a tragedy? What makes $hakespeare's version a different work from its source, which might bear the same name? How many textual variants between two documents merit reproduction of "different" editions? And what gives First Folio rights of authenticity, when other collected versions of Shakespeare were attempted or completed? Even the current First Folio facsimile, the ur-text for many scholars, is a facsimile of thirty compiled copies of that book, when it is likely that due to collating errors, printing corrections, etc., no two copies were identical.
As regards words, what do we make of words like "weyward" which might signify "wayward" or, in another spelling, "weyard," might signify "weird"? The current OED entry for "weird" gives "weyward" as an alternate spelling of this word, but the only instance it cites is this play. Was $hakespeare quoting his source, which uses "weird," or was he re-characterizing the three sister witches? If early modern readers/audience members might have heard "weyward" and registered both denotations, what does a modern editor do when the two words are no longer connotatively linked? "It is a semantic field and not a single word that needs to be retrieved," say Stallybrass and deGrazia--but how?
As regards character, character names were slippery, sometimes added to a script only after it was finished. Dramatis personae lists are irregular at best. Are we to regard $hakespeare's characterization, then, as Alexander Pope did (the first critic to read $hakespeare's plays with dramatis personae lists attached), remarking upon the unique individuation he gives the characters? I'm reminded of Tiffany Stern when she said that, sometimes, there is evidence that $hakespeare had a bit of poetry and just put it in the most convenient mouth, not really considering characterization that much.
And the author himself: I have made a big deal of writing his name $hakespeare, to remind myself that what I am discussing is not the man, but the (marketable) institution. These authors make the same point, noting that sometimes his name is not attached at all (7 of his first 8 plays are anonymous) but other times it seems attached to a play to lend the play authority and value. Furthermore, we have 37 different spellings of his name, and the one we currently use might be a printerly intervention. The long S and the lowercase k characters tended to break when put next to each other, so printers often separated them with a neutral character, - or e, giving us "Shak-speare" or "Shakespeare" or sometimes "Shake-speare." Finally, our notion of $hakespeare, whether as a never-blotting genius or a thoughtful, revising poet, tends to leave out the agency of other authors, with whom he collaborated often.
They end by remarking that paper itself--a bunch of rags cobbled together, beaten to a pulp, expressed as paper, absorbing ink--is a good analogy for what we think of as the works of $hakespeare, with their (sometimes surprising) humble and multifarious beginnings and their necessarily collaborative production.