## Thursday, September 29, 2011

### Understand Statistics

Author:         Alan Graham
Published:     2010
Publisher:     Hodder Education

I am always on the lookout for good ideas to enhance my training and consulting   approaches. Therefore I read from time to time, from a purely pedagogical perspective, introductory level books on the subjects which I am quite well versed with. The intention is to study the manner in which authors introduce the nuances of  a subject to the novices. Statistics is one such subject.
While facilitating the implementation of high CMMI maturity level practices in companies I previously worked for, I felt that the  project managers and senior level management need to have at least a basic knowledge of statistics to properly understand and use the metrics which such organizations churn out. I wish I had read this book then and recommended it to them. I must admit that even I learnt  a few new things in this book.

The book starts with a very warm and personal introduction by the author, where he sets the expectations from this book very clearly. He says " ...the focus is on understanding the key concepts and principles of the subject" and it "...does not provide a comprehensive guide to statistical techniques".

Chapter 1 introduces the subject of statistics. It describes the reasons why learning statistics is a worthwhile exercise; provides examples of everyday situations where knowledge of statistics will be helpful; what kind of statistical questions can be asked and how they are investigated.
Chapter 2 serves as an introduction or a refresher to some basic mathematical concepts which are necessary for understanding statistics.
Chapter 3 & 4, describes different types of graphs - bar chart, pie chart, histograms, scattergraphs etc. - and provides guidelines for choosing the most appropriate type of graph to represent the data.
Chapter 5 deals with the concept of central value ( i.e. mean, median, mode) and the spread (i.e. variance and standard deviation) around the central value.
Chapter 6 entitled Lies and Statistics is perhaps the most useful chapter in this book from a layperson's perspective. In real life we often come across deceptive representation of facts by means of misleading graphs, confusing percentages and inappropriate averages. This chapter tells us how to see through these deceptions and avoid making regrettable decisions based on them.
Chapter 7 introduces us to the sampling techniques viz; random and systematic and also deals with variations in samples and errors associated with sampling.
Chapter 8 tells us how to collect data samples and to check and ensure data accuracy.
Chapter 9 teaches the basics of using a spreadsheet to do data analysis.
Chapter 10 is about interpreting the data in the tables and reorganize the data to make convey the key information  more clearly.
Chapter 11 and 12 deal with concepts of Regression and Correlation respectively.
Chapter 13 and 14 is about Probability. After introducing the concept of probability, probability models like uniform, normal and binomial distributions are discussed.
Chapter 15, the last chapter tells us how to conduct test of significance in terms of z test and binomial test.

This book is one of the best introduction to the principles of statistics I have  ever read. Simple and easy to understand language; packed with practical examples and exercises and interesting stories revolving around statistics.

So if you want to learn statistics, start with this book !