01-04-Stat-Methods-Sample-Size-Power.Rmd

## Sample Size and Power {-}

### Proportions {-}

```{r a8, comment=NA}

library(pwr)

## Univariate Proportion
pwr.p.test(h = .25, sig.level = .05, power = .8, alternative = "greater")

## Two Proportions (equal n)
pwr.2p.test(h = .25, sig.level = .05, power = .8, alternative = "greater")

## Two Proportions (different n)
pwr.2p2n.test(h = .25, n1 = 100, n2 = 120, sig.level = .05, alternative = "greater")
```

### T-test {-}

```{r a9, comment=NA}
## Equal n
pwr.t.test(d = .5, sig.level = .05, power = .8, type = "one.sample")
pwr.t.test(d = .5, sig.level = .05, power = .8, type = "two.sample")
pwr.t.test(d = .5, sig.level = .05, power = .8, type = "paired")

## Different n
pwr.t2n.test(n1 = 10, n2 = 15, d = 1, sig.level = .05)
```

### Chi-square {-}

```{r a10, comment=NA}
pwr.chisq.test(w = .25, df = 4, sig.level = .05, power = .8)
```

### ANOVA {-}

```{r a11, comment=NA}
pwr.anova.test(k = 5, n = 10, f = .5, sig.level = .05)
```