diff --git a/data-design.qmd b/data-design.qmd
index 21757356..e48c69b6 100644
--- a/data-design.qmd
+++ b/data-design.qmd
@@ -735,7 +735,7 @@ Ultimately, this is a difficult situation where we cannot perfectly protect both
 ## Observational studies {#sec-observational-studies}
 
 Studies where no treatment has been explicitly applied (or explicitly withheld) are called **observational studies**\index{study!observational}\index{observational study}.
-For instance, studies on the loan data and county data described in @sec-data-basics are would both be considered observational, as they rely on **observational data**.
+For instance, studies on the loan data and county data described in @sec-data-basics are both considered observational, as they rely on **observational data**.
 
 ```{r}
 #| include: false