Niall Harrison has pronounced himself an interstitial skeptic, and there's been interesting discussion in the comments to the post.
Here's what I submitted when asked for an introduction to my story that would explain how it is interstitial:
Today the only labels I like for what I write are Wishes and Exorcisms. Sometimes the two labels overlap, like searchlights finding each other in a dark sky.In some ways, I was being coy. In more ways, I was being honest.
A few months before he died in 1904, Anton Chekhov wrote to his wife, an actress in Moscow. He was forty-four years old, living in Yalta, and in the last stages of tuberculosis, a disease he had suffered from for almost half his life, a disease that had claimed his brother, Nikolai, in 1889. He wrote, "You ask: What is life? That's just like asking: What is a carrot? A carrot is a carrot, and that's all we know."
I want my stories to be like life, which means I want them to be like carrots, which means each story is a story, and that's all we know.
But I wrote the story for the anthology, and so at a very basic level of definition it is interstitial, because I wrote it with the book in mind, it was accepted by the editors, and will now appear with that label attached to it. It will be read as an example of something that I can't define, and I love the weirdness of that. Before writing the story, I read everything I could find about what "interstitial" meant to the IAF, and I still really couldn't put my finger on it, so I decided to take the word literally and write a story that crossed as many borders as I could think of while writing it. Writing it felt similar to writing "The Art of Comedy", and I think of the two stories as part of a sort of loose trilogy for which I haven't yet written the third piece.
"Interstitial fiction", then, has been useful to me as a way of creating a story I might not otherwise have created, and the term opened up a space -- the anthology -- in which that story could appear. More than that I would not want to claim for the term, though I'm certainly not opposed to people doing so. We all have different levels of comfort with labels. Whenever I encounter a label or definition of any sort, I have an overwhelming urge to find its exceptions and limitations. This could be a form of psychosis rather than a valid critical instinct.
Any label a reader encounters for a story will affect how that story is read, and so labels offer both a way of seeing and a way of not seeing. I hope the label of "interstitial" will help readers notice all the border-crossings in my story, because I think that will make it a richer reading experience than it would be otherwise, but I know, too, that the label will obscure things within the story. But things get obscured for all sorts of reasons, and no reading is ever comprehensive. I'm too much of a postmodernist to believe in any sort of "pure" reading. My hope would be that the stories could live both with and without the label, that they could acquire other labels and other ways of reading, that their meanings could expand and multiply, gaining richness and power. Without delineations we could see nothing -- we have to be able to say this is this and not that, we have to be able to distinguish, but there is no need to let the tools of distinguishing become chains. We need labels to show us what we would not see otherwise, but when the labels become more blinding than enlightening, they must be cast aside -- and any honest label-maker would, I hope, agree.