The Fourth Edition has been updated in four primary ways: it much more prominently addresses the growth of the Internet for data collection and the subsequent rapid expansion of online survey usage; it addresses the precipitous drop in response rates for telephone surveys, particularly those based on random-digit dialing; it offers new and expanded coverage monitoring the continued improvement in techniques for presurvey evaluation of questions; and it addresses the growing role of individual cell phone in addition - and often instead of - household landlines.

Two new chapters, "The Nature of Error in Surveys" and "Issues in Analyzing Survey Data," further emphasize the importance of minimizing nonsampling errors through superior question design, quality interviewing, and high response rates.