Strategies to Approximate Random Sampling and Assignment
Patrick Dattalo
Abstract
Random sampling (RS) and random assignment (RA) are considered by many researchers to be the definitive methodological procedures for maximizing external and internal validity. However, there is a daunting list of legal, ethical, and practical barriers to implementing RS and RA. While there are no easy ways to overcome these barriers, social workers should seek and utilize strategies that minimize sampling and assignment bias. This book is a single source of a diverse set of tools that will maximize a study's validity when RS and RA are neither possible nor practical. Readers are guided in sel ... More
Random sampling (RS) and random assignment (RA) are considered by many researchers to be the definitive methodological procedures for maximizing external and internal validity. However, there is a daunting list of legal, ethical, and practical barriers to implementing RS and RA. While there are no easy ways to overcome these barriers, social workers should seek and utilize strategies that minimize sampling and assignment bias. This book is a single source of a diverse set of tools that will maximize a study's validity when RS and RA are neither possible nor practical. Readers are guided in selecting and implementing an appropriate strategy, including exemplar sampling, sequential sampling, randomization tests, multiple imputation, mean-score logistic regression, partial randomization, constructed comparison groups, propensity scores, and instrumental variables methods. Each approach is presented in such a way as to highlight its underlying assumptions, implementation strategies, and strengths and weaknesses.
Keywords:
random sampling,
random assignment,
exemplar sampling,
sequential sampling,
randomization tests,
multiple imputation,
mean-score logistic regression,
sequential assignment and treatment-as-usual combined,
partial randomization,
constructed comparison groups,
instrumental variables methods,
propensity scores
Bibliographic Information
Print publication date: 2009 |
Print ISBN-13: 9780195378351 |
Published to Oxford Scholarship Online: February 2010 |
DOI:10.1093/acprof:oso/9780195378351.001.0001 |