\begin{Schunk}
\begin{Sinput}
 x.null <- seq(-4, 4, .1)
 dx.null <- dnorm(x.null, m = 0, s = 0.5)
 plot(x.null, dx.null, type = "l", lwd = 2, xlim = c(-4, 8), yaxt = "n",
  xlab = "Effect Size (e.g., Mean-Difference between Groups)", ylab = "")
 ## If abs(z) > 1.96, reject the null at alpha = .05
 abline(v = qnorm(c(.025, .975), m = 0, s = 0.5), lwd = 2, lty = "dashed")
 ## Type I errors occur for observations drawn outside the dashed lin
 x.1 <- c(x.null + 1)
 dx.1 <- dnorm(x.8, m = 1, s = 0.5)
 lines(x.1, dx.1, lwd = 2, col = "red")
\end{Sinput}
\end{Schunk}
