A fix-up (or fixup) is a novel created from several short fiction stories that may or may not have been initially related or previously published.
Foreshadowing of events from the later stories may be jammed into an early chapter of the fix-up, and character development may be interleaved throughout the book.
Some fix-ups in their final form are more of a short story cycle or composite novel, rather than a traditional novel with a single main plotline.
Large book publishers like Doubleday and Simon & Schuster entered the market, greatly increasing demand for fiction.
Algis Budrys in 1965 described fixups as a consequence of the lack of good supply during the "bad years for quality" of the mid-1950s, although citing The Martian Chronicles and Clifford D. Simak's City as exceptions.