diff --git a/.obsidian/plugins/obsidian-git/data.json b/.obsidian/plugins/obsidian-git/data.json
index 7b1247f..4bc189e 100644
--- a/.obsidian/plugins/obsidian-git/data.json
+++ b/.obsidian/plugins/obsidian-git/data.json
@@ -2,7 +2,7 @@
   "commitMessage": "vault backup: {{date}}",
   "autoCommitMessage": "vault backup: {{date}}",
   "commitDateFormat": "YYYY-MM-DD HH:mm:ss",
-  "autoSaveInterval": 1,
+  "autoSaveInterval": 5,
   "autoPushInterval": 0,
   "autoPullInterval": 5,
   "autoPullOnBoot": false,
diff --git a/education/statistics/Correlation and Regression.md b/education/statistics/Correlation and Regression.md
index 40689d5..4f93bbb 100644
--- a/education/statistics/Correlation and Regression.md	
+++ b/education/statistics/Correlation and Regression.md	
@@ -51,4 +51,6 @@ https://www.thoughtco.com/how-to-calculate-the-correlation-coefficient-3126228
 - $r$ does not change if you:
 	- switch the $x$ and $y$ values
 	- add the same number to every x or y value
-	- multiply each $x$ or $y$ value by a positive number
\ No newline at end of file
+	- multiply each $x$ or $y$ value by a positive number
+- The correlation coefficient can be misleading in the presence of outliers or nonlinear association. 
+- $r$ only shows the strength of a linear relationship.
\ No newline at end of file