Statistics for Real-Life Sample Surveys: Non-Simple-Random Samples and Weighted DataSamples used in social and commercial surveys, especially of the general population, are usually less random (often by design) than many people using them realise. Unless it is understood, this 'non randomness' can compromise the conclusions drawn from the data. This book introduces the challenges posed by less than perfect samples, giving background knowledge and practical guidance for those who have to deal with them. It explains why samples are,