Unformatted text preview: hypothesis. • If you insist on higher power (such as 99% rather than 90%), you will need a larger sample. Higher power gives a better chance of detecting an effect when it is really there. • At any significance level and desired power, a two-sided alternative requires a larger sample than a one-sided alternative. • At any significance level and desired power, detecting a small effect requires a larger sample than detecting a large effect. The significance level of a test is the probability of reaching the wrong conclusion when the null hypothesis is true. The power for a specific alternative is the probability of reaching the right conclusion when that alternative is true....
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- Winter '11
- Statistics, Statistical hypothesis testing, Statistical significance, significance level, Statistical power, Effect size