This book is frustrating to say the least. It just brushes certain topics, leaving out valuable information - that could have easily been included. For example the topic of passing a dataframe to a sapply or lapply is touched but the why, how, when,... etc are never explained. When reading this or many other sections in this book you cannot help but feel there is a lot of important information regarding these topics you simply still don't know about. Even for a Beginners Guide it leaves out far too much information to be really useful. Some parts might be quite good but the holes in the information this book presents are simply too glaringly huge - if you're looking for a good primer for R, better look somewhere else.