diff --git a/README.md b/README.md
index 64cbf5159..c775c9776 100644
--- a/README.md
+++ b/README.md
@@ -2,9 +2,10 @@ xgboost: eXtreme Gradient Boosting
 =======
 An optimized general purpose gradient boosting (tree) library.
 
-Authors:
+Contributors:
 * Tianqi Chen, project creater
 * Kailong Chen, contributes regression module
+* Bing Xu, contributes python interface, higgs example
 
 Turorial and Documentation: https://github.com/tqchen/xgboost/wiki
  
diff --git a/demo/kaggle-higgs/README.md b/demo/kaggle-higgs/README.md
index a3c208002..b3db23266 100644
--- a/demo/kaggle-higgs/README.md
+++ b/demo/kaggle-higgs/README.md
@@ -16,5 +16,6 @@ make
 
 
 
-
+Speed
+=====
 speedtest.py compares xgboost's speed on this dataset with sklearn.GBM
diff --git a/demo/rank/runexp.sh b/demo/rank/runexp.sh
index d948ca5a0..c17ebee05 100755
--- a/demo/rank/runexp.sh
+++ b/demo/rank/runexp.sh
@@ -1,7 +1,17 @@
-python trans_data.py train.txt mq2008.train mq2008.train.group
-python trans_data.py test.txt mq2008.test mq2008.test.group
-python trans_data.py vali.txt mq2008.vali mq2008.vali.group
+#Download the dataset from web site
+wget http://research.microsoft.com/en-us/um/beijing/projects/letor/LETOR4.0/Data/MQ2008.rar
+
+#please first install the unrar package
+unrar x MQ2008
+
+python trans_data.py MQ2008/Fold1/train.txt mq2008.train mq2008.train.group
+
+python trans_data.py MQ2008/Fold1/test.txt mq2008.test mq2008.test.group
+
+python trans_data.py MQ2008/Fold1/vali.txt mq2008.vali mq2008.vali.group
 
 ../../xgboost mq2008.conf
+
 ../../xgboost mq2008.conf task=pred model_in=0004.model
 
+
diff --git a/python/example/demo.py b/python/example/demo.py
index f5e0aa2a7..73935efab 100755
--- a/python/example/demo.py
+++ b/python/example/demo.py
@@ -12,7 +12,7 @@ dtrain = xgb.DMatrix('agaricus.txt.train')
 dtest = xgb.DMatrix('agaricus.txt.test')
 
 # specify parameters via map, definition are same as c++ version
-param = {'bst:max_depth':2, 'bst:eta':1, 'silent':1, 'loss_type':2 }
+param = {'bst:max_depth':2, 'bst:eta':1, 'silent':1, 'objective':'binary:logistic' }
 
 # specify validations set to watch performance
 evallist  = [(dtest,'eval'), (dtrain,'train')]
@@ -29,11 +29,6 @@ bst.dump_model('dump.raw.txt')
 # dump model with feature map
 bst.dump_model('dump.raw.txt','featmap.txt')
 
-# beta: interact mode
-bst.set_param('bst:interact:expand',4)
-bst.update_interact( dtrain, 'update', 0)
-bst.dump_model('dump.raw2.txt')
-
 ###
 # build dmatrix in python iteratively
 #
diff --git a/python/xgboost.py b/python/xgboost.py
index 5c3555770..d7cf9f63e 100644
--- a/python/xgboost.py
+++ b/python/xgboost.py
@@ -1,3 +1,4 @@
+# Author: Tianqi Chen, Bing Xu
 # module for xgboost
 import ctypes 
 import os
diff --git a/python/xgboost_python.cpp b/python/xgboost_python.cpp
index 8dd210c52..7c63fc6ac 100644
--- a/python/xgboost_python.cpp
+++ b/python/xgboost_python.cpp
@@ -1,3 +1,4 @@
+// implementations in ctypes
 #include "xgboost_python.h"
 #include "../regrank/xgboost_regrank.h"
 #include "../regrank/xgboost_regrank_data.h"
diff --git a/python/xgboost_python.h b/python/xgboost_python.h
index ac3ca94ac..6c113a108 100644
--- a/python/xgboost_python.h
+++ b/python/xgboost_python.h
@@ -1,7 +1,8 @@
 #ifndef XGBOOST_PYTHON_H
 #define XGBOOST_PYTHON_H
 /*!
- * \file xgboost_regrank_data.h
+ * \file xgboost_python.h
+ * \author Tianqi Chen
  * \brief python wrapper for xgboost, using ctypes, 
  *        hides everything behind functions
  *      use c style interface