Statistical power: Difference between revisions
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*null hypothesis: there is no relationship between two measured phenomena | *null hypothesis: there is no relationship between two measured phenomena | ||
**often denoted H0 (read “H-nought”, "H-null", or "H-zero") | **often denoted H0 (read “H-nought”, "H-null", or "H-zero") | ||
*alternative hypothesis: there is a significant relationship between the two measured phenomena | |||
**often denoted H1 | |||
==Common Statistical Terms== | ==Common Statistical Terms== | ||
SYMBOLS | |||
*α: probability of type I error | *α: probability of type I error | ||
*β: probability of type II error | *β: probability of type II error | ||
*χ²: ≥ 2 percentages or proportions of categorical outcomes | |||
TERMS | |||
*ANOVA: compares means of ≥ 3 groups | |||
*Confidence interval: range in which real mean expected to fall | |||
*Negative skew: mean < median < mode | |||
*Positive skew: mean > median > mode | |||
*Power: probability of correctly rejecting H0 | *Power: probability of correctly rejecting H0 | ||
**to increase power increase sample size (most important), and/or increase expected effect size, and/or increase precision of measurement | |||
*Standard deviation: variability from mean | *Standard deviation: variability from mean | ||
*Standard error of the mean: variability between sample mean and true mean | *Standard error of the mean: variability between sample mean and true mean | ||
*t test: compares means of 2 groups | *t test: compares means of 2 groups | ||
* | *Type I error: H0 incorrectly rejected | ||
* | *Type II error: H0 incorrectly accepted | ||
==Also See== | ==Also See== | ||
Latest revision as of 20:58, 28 July 2016
Background
- null hypothesis: there is no relationship between two measured phenomena
- often denoted H0 (read “H-nought”, "H-null", or "H-zero")
- alternative hypothesis: there is a significant relationship between the two measured phenomena
- often denoted H1
Common Statistical Terms
SYMBOLS
- α: probability of type I error
- β: probability of type II error
- χ²: ≥ 2 percentages or proportions of categorical outcomes
TERMS
- ANOVA: compares means of ≥ 3 groups
- Confidence interval: range in which real mean expected to fall
- Negative skew: mean < median < mode
- Positive skew: mean > median > mode
- Power: probability of correctly rejecting H0
- to increase power increase sample size (most important), and/or increase expected effect size, and/or increase precision of measurement
- Standard deviation: variability from mean
- Standard error of the mean: variability between sample mean and true mean
- t test: compares means of 2 groups
- Type I error: H0 incorrectly rejected
- Type II error: H0 incorrectly accepted