diff --git a/education/statistics/Measurement Error.md b/education/statistics/Measurement Error.md
index 840e6fb..f5795fe 100644
--- a/education/statistics/Measurement Error.md	
+++ b/education/statistics/Measurement Error.md	
@@ -6,3 +6,14 @@ Bias *affects all measurements the same way, making them all too large or too sm
 ## Chance error
 Chance errors *change from measurement to measurement but average out over time*. There is no way to remove all chance errors from a measuring process. An example of chance error would be starting a stopwatch then attempting to stop it at exactly 5 seconds, then repeating. The times will vary, but each measurement will vary in a different way.
 
+- Chance error is how much an individual measurement varies from the exact value. It can be positive or negative.
+- The standard deviation of repeated measurements gives us the expected size of a chance error
+```
+individual measurement = exact value + chance error
+```
+
+# Terminology
+| Term | Definition |
+| -- | -- |
+| Best Guess | Average/Mean |
+| Off by how much | standard deviation |