diff --git a/00-preface.Rmd b/00-preface.Rmd
index e3d1c43d..f9a3fe9d 100644
--- a/00-preface.Rmd
+++ b/00-preface.Rmd
@@ -10,7 +10,7 @@ We hope readers will take away three ideas from this book in addition to forming
 
 1.  **Introduction to data.** Data structures, variables, summaries, graphics, and basic data collection techniques.
 2.  **Exploratory data analysis.** Data visualization and summarisation.
-3.  **Correlation and regression.** Visualising relationships between many variables and descriptive summaries for quantifying the relationship between two variables.
+3.  **Correlation and regression.** Visualizing relationships between many variables and descriptive summaries for quantifying the relationship between two variables.
 4.  **Multiple regression.** Descriptive summaries for quantifying the relationship between two variables.
 5.  **Foundations for inference.** Case studies are used to introduce the ideas of statistical inference with randomization and simulations.
 6.  **Inference for categorical data.** Inference for proportions using simulation and randomization techniques as well as the normal and chi-square distributions.