Denna fråga besvarades av Fletcher Pratt i de inledande styckena (citerade nedan) i hans introduktion till Martin Greenbergs 1951-antologi Journey to Infinity :
Science fiction is unique among the modern groupings of literature in that the anthology is perhaps its most typical form. Not that there are no book-length novels in the field. There are some extremely good ones; but the method and material of science fiction lend themselves particularly well to the short story. The writer of science fiction is and must be concerned with the reactions of human beings in environments which, either by time or circumstance, are strikingly different from the world in which we spend our daily lives. If that writer elaborates the picture of his imagined world in every last logical detail, he risks losing track of the individual people he is writing about. That is, he turns out a treatise instead of a story; and in fact much book-length science fiction is more science than fiction, Bellamy's Looking Backward being a famous example. The writer who is really telling a story can normally afford only a glimpse of the different world in which his tale is laid, enough to indicate its main lines and why it is provided with pleasures, duties and perils unlike those that normally surround us.
Moreover, science fiction appears largely in magazines for the first time, and the modern American magazine reader has established his perfectly reasonable repugnance to being bothered either with very long stories or losing the thread of a type of story that always requires rather close reading while waiting for the next issue to come out. The short story has thus come to dominate the field of science fiction, and it is not surprising that various people have found many short stories too good to be left gathering dust in piles of back number magazines.