The use of "bug" in computing

There has been much speculation concerning the early use of the word "bug" in the language of computer science, technology, and practice. The purpose of the article is to indicate what may be the earliest application of "bug" in the context of computers. When the IBM ASCC/Harvard Mark I was installed at Harvard University, Robert V.D. Campbell was in charge of the operation of the machine. Bob Campbell supervised the testing and first runs of the machine and remained in charge of the machine and its operation until the spring of 1944. Campbell kept a detailed log book, recording almost every aspect of the operation of the new machine, including the preparation of the first programs and the various kinds of difficulties that arose. On April 17 1944, Campbell recorded an entry in which reference was made to "bugs" in the ASCC/Mark 1. This is thought to be the first mention of the word "bug" in relation to a computer.<>