What Hollywood Can Teach Us about Software Testing
- 3. What Hollywood Can Teach Us about Software Testing Bernie Berger BSC West, Las Vegas June 8, 2016
- 4. Five Key Points in this Presentation Testing Lesson 1. Beware of Off-by-One Errors 2. Enhance Situational Awareness 3. Recognize Inattentional Blindness 4. Test Opportunistically 5. Consider alternate explanations Movie • Office Space (1999) • Sneakers (1992) • Star Trek II: The Wrath of Khan (1982) • Saving Private Ryan (1998) • All the President’s Men (1976) There are many other lessons all around us, if you learn to appreciate them
- 5. Key Point #1: Beware of Off-by-One Errors Office Space (1999)
- 6. 1. The Scene: Office Space
- 7. 1. Off-by-One (& Order of Magnitude) Errors • Decimal Points in wrong place • Flag set on when it should be off • Loop initialized at 1 instead of 0 • Comparison >= instead of just > • Or vice versa • One line of code commented out
- 8. Key Point #2: Enhance Situational Awareness Sneakers (1992)
- 9. 2. The Scene: Sneakers
- 10. 2. Testing and Situational Awareness • Situational Awareness is a testing skill • Be aware of your own biases • Be aware of whom you can ask questions • Be aware of the many available sources of information • Be aware of the many ways tests can fail • Be aware of your own confusion • Be aware of tools and technology Wikipedia: “One with an adept sense of situation awareness generally has a high degree of knowledge with respect to inputs and outputs of a system, an innate "feel" for situations, people, and events”
- 11. Key Point #3: Recognize Inattentional Blindness Star Trek II: The Wrath of Khan (1982)
- 12. 3. The Scene: Star Trek II: The Wrath of Khan
- 13. 3. Testing and Inattentional Blindness • We don’t see what we don’t pay attention to, even if it’s right in front of our eyes. • Hard to reproduce bugs happen when we are not monitoring relevant variables. • Defocusing Heuristic • The flip side of Situational Awareness The brain is constantly bombarded by far more information that it can handle. If we tried to process all of it we'd be completely paralyzed. As a result we have to attend to only a small part of what's in front of us at any given moment. The brain picks and choses according to what it thinks is important. If you change something that it doesn't think is important you just literally don't see it.
- 14. Key Point #4: Exploratory Testing: Test Opportunistically Saving Private Ryan (1998)
- 15. 4. The Scene: Saving Private Ryan
- 16. 4. Opportunistic Exploratory Testing “Opportunity testing is any testing that doesn’t fit the charter of the session. Since we’re in doing exploratory testing, we remind and encourage testers that it’s okay to divert from their charter if they stumble into an off- charter problem that looks important.” -Jonathan Bach, Session Based Test Management Pure Scripted Pure Exploration The “tour bus” Principle Even people on a tour bus get to step off it occasionally and wander around. The key is not to miss the tour entirely, nor to fall asleep on the bus.
- 17. Key Point #5: Context of Discovery: Consider alternate explanations All the President’s Men (1976)
- 18. 5. The Scene: All the President’s Men
- 19. 5. Testing and Context of Discovery • Absolute Language vs. Safety Language • Consider Alternate Explanations • Don’t Jump to Conclusions • Bug Reporting: • Facts and Data • Speculative Deduction
- 20. Conclusion Be personally involved! Midnight Run (1988)
- 21. Get Personally Involved In Your Work!
- 22. Beware of Off-by-One Errors Exhibit Situational Awareness Test Opportunistically Consider alternate explanations Recognize Inattentional Blindness Get Personally Involved! Thank You!