Quote: design flaws are inevitable; use defense-in-depth to avoid, find, and survive mistakes [»colwRP_2006]

Quote: programming is difficult because it is almost impossible to avoid blunders; main difficulty in using computers [»glenAE2_1953]

Quote: everyone makes dumb mistakes; a huge number of bugs are just one step away from a syntax error; e.g., typing || instead of && [»hoveD12_2004]

Quote: it is easy to make expensive programming errors; the EDSAC group developed techniques to avoid or detect errors before execution and to locate errors after execution [»wilkMV_1951]

Quote: errors occur frequently in numeric tables; corrections to the Nautical Almanac were themselves in error [»babbC_1864, OK]

Quote: system accidents naturally occur in systems with interactive complexity and tight coupling; e.g., nuclear power plants [»perrC_1984]

Quote: the cards for the Analytical Engine may contain errors; but once developed, they are valid for an infinite number of particular cases [»menaLF10_1842, OK]

Quote: running the web crawler generated a fair amount of e-mail and phone calls; need to solve problems as they occur [»brinS4_1998]

Quote: the New York Times contains about one mistake per thousand; similar to programmers [»holzGJ11_2002]

Quote: experimentally derived protocols for TCP/IP and Sockets identified many behavioural anomalies and explicit OS version dependencies [»bishS1_2006]

Quote: a software error is unintended phenomenon in either the specification or program [»hamiM_1978]

Quote: a lot of debugging is knowing which structures are intact; i.e., a bug is the breaking of some structure [»cbb_1973, OK]

Quote: a software error is a combination of illegal actions, incorrect paths, and wrong results [»abboRJ3_1990]

Quote: in a digital device, changing a single bit can have drastic consequences; a radical novelty of computers [»dijkEW12_1989]

Quote: a decomposition error occurs when a programmer makes a false assumption about some other part of the program

Quote: software errors often occur when information is lost because it is not part of the program [»howdWE1_1990]

Quote: report all sightings of bugs; incidents that could have a bug as its cause; a validation engineer attempts to reproduce it [»colwRP_2006]

Quote: identifying a misconfiguration of a fully-racked, benchmark machine took nearly a week, full-time, around the globe [»cantB2_2006]

Quote: change is the primary agent of faults; large, recent changes are the most likely to fail; frequency of change is a better predictor of faults than size of module or number of developers [»eickSG1_2001]

Quote: faults tend to concentrate in a few files; by Release 13, faults in 4% of files; partially due to file size and system growth [»ostrTJ7_2002]

Quote: in every release, as many post-release faults were in files with no late-pre-release faults as were found in files with late-pre-release faults [»ostrTJ7_2002]

Quote: moderate evidence that files with many faults in one release remain high-fault files in later releases [»ostrTJ7_2002]

Quote: fixing a release bug is twice as difficult as fixing pre-release bug

Quote: studied bug history of NAG library; bugs proportional to logarithm of complexity [»hattL3_1997]

Quote: smaller components have disproportionally more bugs; best may be 200-400 lines of code

Quote: larger files had lower fault densities [»ostrTJ7_2002]

Quote: C++ bugs took twice as long to correct as C bugs; C++ failure may be a long way away from the error [»hattL5_1998]

Quote: difficult to test non-deterministic software because of limited observability and limited controllability [»holzGJ11_2002]

Quote: use static analysis, symbolic interpretation, reachability, and logic model checking for non-deterministic software; but bugs will still remain

Quote: PL.8 optimizer bugs produce catastrophic results since optimizer applies to all code; regression test of 150 self-checking programs [»auslM6_1982]

Quote: visually inspect every bit of analysis and code; most errors are obvious [»roycWW8_1970]

Quote: with enough testers and developers, every problem can be identified and fixed easily; debugging is parallelizable, unlike development [»raymES3_1998]

Quote: check sheets miss errors due to preconceived ideas, insufficient test cases, not checking alterations, or alternating check sheet but not the program [»turiA3_1951]

Quote: programs can be nonsense, illegal, almost working, fragile, suspicious, wrong, or correct [»scowRS3_1982b, OK]

Quote: a mild bug offends aesthetically: spelling error or misaligned printout

Quote: a disturbing bug refuses to handle legitimate transactions

Quote: an intolerable bug corrupts the database invisibly; the system should be shut down [»beizB_1984]

Quote: short, anonymous error reports by symbolic execution of failed executions and an SMT solver of the path expression; Satisfiability Modulo Theory [»castM3_2008]

Quote: if a bug sighting is not reproducible, move it to the anomalies list; remove from the sightings/bug database [»colwRP_2006]

Quote: use bug checkers for latent bugs; e.g., a covariant equals method works until someone adds the class to a map or set; another latent bug is hashcode/equals [»hoveD12_2004]

Quote: should not call them 'bugs' because they are really errors; they don't maliciously sneak in [»dijkEW12_1989]

Quote: a program fails because of a new input sequence; so can talk about the failure rate of software [»parnDL6_1990]

Quote: an infectious bug corrupts other systems; e.g., a nuclear meltdown or causes a war [»beizB_1984]

Quote: structuring a program almost halves the frequency of ripple effect errors [»gibsVR3_1989]

Quote: for every bug ask: is it somewhere else, what bugs does this hide, how is this type of bug prevented [»vanvT7_1989]

Quote: identify erroneous changes by finding bug fixes that changed the same lines as another change [»puruR6_2005]

Quote: 40% of changes to fix errors introduced more errors [»puruR6_2005]

Quote: human errors are intrinsic to being human [»parnDL2_1986]

Quote: simulated SmartHelp messages had to be generated on the fly since users were too creative and quick in generating errors and misconceptions [»carrJM9_1988]

Quote: a capture error occurs when a frequently done activity captures an unfamiliar activity sharing the same initial stages [»normDA_1988]

Quote: software errors can always be attributed to transient hardware errors [»leveNG7_1993]

Quote: several techniques for delaying or dropping excessive interrupt requests; bounds the work, granularity, and rate of the interrupt context; e.g., the first moon landing nearly aborted due to interrupt overload [»regeJ6_2005]

Quote: early problems with the Therac-25 were blamed on the hardware

Quote: computers do not guarantee absence of hardware faults; breaks proof of soundness of link-time type-checking; e.g., cosmic rays or heat-induced faults [»goviS5_2003]

Quote: for hardware failures, 30% memory, 26% disk, 17% processor; for driver failures, 35% display, 13% anti-virus, 10% CD-burning, 9% audio, 9% modem

Quote: list of all corrections to TEX over 10 years [»knutDE7_1989]

Quote: fault analysis of the first 13 releases of an inventory tracking system; 500,000 lines of code, mostly Java [»ostrTJ7_2002]

Quote: CCured identified bugs in ks, compress, ijpeg, and go [»necuGC5_2005]

Quote: most bugs detected prior to beta release; 10 of 78 severity 1 faults detected after release [»ostrTJ7_2002]

Quote: assign one file per fault; if corrected by modifying n files, counts as n faults [»ostrTJ7_2002]

Quote: an experimental study of spreadsheets found 44% contained an error [»browPS7_1987]

Quote: the largest source of errors in nucleotide sequence data is transcription errors during publication

Quote: many operating systems will crash and require a complete restart; often due to incorrect coordination of concurrent activity; better now [»dennPJ_1980]

QuoteRef: boehBW5_1973 ;;57 manned space flight eg Apollo 14 18 errors found (non-fatal)

QuoteRef: boehBW5_1973 ;;57 French meteorological satellite lost 72 of 141 weather balloons cause of bug, early Mariner was lost

Quote: the Ballistic Missile System Early Warning System failed because of the rising moon