dealing with real-world data bias/variance trade-off -fold cross-validation to avoid overfitting example of -fold cross-validation using scikit-learn data cleaning and normalisation cleaning web log data applying regular expression on the web log modification one filtering the request field modification two filtering post requests modification three checking the user agents modification four applying website-specific filters activity for web log data normalizing numerical data detecting outliers dealing with outliers activity for outliers summary apache spark machine learning on big data installing spark installing spark on windows installing spark on other operating systems installing the java development kit installing spark spark introduction it' scalable it' fast it' young it' not difficult components of spark python versus scala for spark spark and resilient distributed datasets (rddthe sparkcontext object creating rdds filtering the activity of spiders/robots creating an rdd using python list loading an rdd from text file more ways to create rdds rdd operations vi