Biology 2244A/B Lecture Notes - Lecture 5: Contingency Table, Frequentist Probability, Conditional Probability

• School: Western University
• Department: Biology
• Course: Biology 2244A/B
• Professor: Angela White

Document Summary

A measure of the long-run relative frequency of an event occurring, in identical repeated trials. Classical approach: make an assumption about the theoretical probabilities. Random outcome: uncertain, but follows a regular distribution in a large number of repetitions. Probability of a random outcome: proportion of times the outcome would occur in a long series of repetitions. Random sampling: each unit has an equal chance. Random outcomes: predictable probability but not equally likely, some outcomes would be relatively more favorable. It"s possi(cid:271)le to flip a (cid:272)oi(cid:374) (cid:1005)(cid:1004)(cid:1004) ti(cid:373)es a(cid:374)d get (cid:1005)(cid:1004)(cid:1004) heads o(cid:374) a ro(cid:449), u(cid:374)likely (cid:271)ut possi(cid:271)le. The relative frequency probability of an event tends to approach the actual probability as a procedure is repeated. The more and more you do, the closer we get the real probability. Illustrate when you do something only a couple of times- bounce up and down. Repeat more steady, assume to be real probability. Also called: contingency table, works in two ways.