Abduction reasoning draw conclusion based on the explanation that best explains the current state of events rather than from evidence provided by the premises.
Sherlock Holmes “When you have eliminated the impossible, whatever remains, however improbable, must be the truth”
e.g.
- Anna told you she failed her physics midterm.
- Anna hasn’t been in physics class since your teacher graded the exams.
- Anna has been in sociology class, which meets right after physics. Conclusion: Anna dropped physics
Another
- You and your roommate ate sushi last night.
- You both wake up with violent stomach aches. Conclusion: You and your roommate ate some bad sushi
Abduction also can’t provide certainty.