diff --git a/demo/kaggle-otto/understandingXGBoostModel.Rmd b/demo/kaggle-otto/understandingXGBoostModel.Rmd
index f0858e2da..6bd64401d 100644
--- a/demo/kaggle-otto/understandingXGBoostModel.Rmd
+++ b/demo/kaggle-otto/understandingXGBoostModel.Rmd
@@ -45,7 +45,7 @@ dim(train)
 train[1:6,1:5, with =F]
 
 # Test dataset dimensions
-dim(train)
+dim(test)
 
 # Test content
 test[1:6,1:5, with =F]
@@ -228,4 +228,4 @@ There are 4 documents you may also be interested in:
 * [xgboostPresentation.Rmd](https://github.com/dmlc/xgboost/blob/master/R-package/vignettes/xgboostPresentation.Rmd): general presentation
 * [discoverYourData.Rmd](https://github.com/dmlc/xgboost/blob/master/R-package/vignettes/discoverYourData.Rmd): explaining feature analysus
 * [Feature Importance Analysis with XGBoost in Tax audit](http://fr.slideshare.net/MichaelBENESTY/feature-importance-analysis-with-xgboost-in-tax-audit): use case
-* [The Elements of Statistical Learning](http://statweb.stanford.edu/~tibs/ElemStatLearn/): very good book to have a good understanding of the model
\ No newline at end of file
+* [The Elements of Statistical Learning](http://statweb.stanford.edu/~tibs/ElemStatLearn/): very good book to have a good understanding of the model