The second article below is the best introduction to MOST.  To understand the conceptual issues underlying the design decisions, however, these articles are best read together, in the following order:

Baker, T. B., Mermelstein, R. J., Collins, L. M., Piper, M. E., Jorenby, D. E., Smith, S. S., Schlam, T. R. Cook, J. W., & Fiore, M. C. (2011). New methods for tobacco dependence treatment research. Annals of Behavioral Medicine, 41, 192-207. PMCID: PMC3073306  View abstract

Collins, L. M., Baker, T. B., Mermelstein, R. J., Piper, M. E., Jorenby, D. E., Smith, S. S., Schlam, T. R., Cook, J. W., & Fiore, M. C. (2011). The multiphase optimization strategy for engineering effective tobacco use interventions. Annals of Behavioral Medicine, 41, 208-226. PMCID: PMC3053423  View abstract

These articles describe the thinking behind some implementations of MOST or related approaches in field settings.  They describe factorial experiments in varying stages of completion.

Caldwell, L. L., Smith, E. A., Collins, L. M., Graham, J. W., Lai, M., Wegner, L., Vergnani, T., Matthews, C., & Jacobs, J. (2012). Translational research in South Africa: Evaluating implementation quality using a factorial design. Child and Youth Care Forum, 41, 119-136. PMCID: PMC3375728

Strecher, V. J., McClure, J. B., Alexander, G. W., Chakraborty, B., Nair, V. N., Konkel, J. M., Greene, S. M., Collins, L. M., Carlier, C. C., Wiese, C. J., Little, R. J., Pomerleau, C. S., & Pomerleau, O. F. (2008). Web-based smoking cessation programs: Results of a randomized trial. American Journal of Preventive Medicine, 34, 373-381. PMCID: PMC2697448  View article

McClure, J. B., Derry, H., Riggs, K. R., Westbrook, E. W., St. John, J., Shortreed, S. M., Bogart, A., & An, L. C. (2012). Questions about quitting (Q(2)): Design and methods of a Multiphase Optimization Strategy (MOST) randomized screening experiment for an online, motivational smoking cessation intervention. Contemporary Clinical Trials, 33(5), 1094-1102. PMCID: PMC3408878 View article

To understand the conceptual issues underlying the design decisions, these articles are best read together, in the following order:

Baker, T. B., Mermelstein, R. J., Collins, L. M., Piper, M. E., Jorenby, D. E., Smith, S. S., Schlam, T. R. Cook, J. W., & Fiore, M. C. (2011). New methods for tobacco dependence treatment research. Annals of Behavioral Medicine, 41, 192-207. PMCID: PMC3073306  View abstract

Collins, L. M., Baker, T. B., Mermelstein, R. J., Piper, M. E., Jorenby, D. E., Smith, S. S., Schlam, T. R., Cook, J. W., & Fiore, M. C. (2011). The multiphase optimization strategy for engineering effective tobacco use interventions. Annals of Behavioral Medicine, 41, 208-226. PMCID: PMC3053423  View abstract

These articles review practical aspects of experimental design relevant to intervention science, and also attempt to correct some pervasively held misconceptions.  Charkraborty et al. and Nair et al. are aimed at biostatisticians and health scientists, whereas Collins et al. and Dziak et al. are aimed at behavioral scientists.  These articles provide a rationale for considering a factorial experiment and may be useful citations.

Chakraborty, B., Collins, L. M., Strecher, V., and Murphy, S. A. (2009). Developing multicomponent interventions using fractional factorial designs. Statistics in Medicine, 28, 2687-2708. PMCID: PMC2746448  View article

Collins, L. M., Dziak, J. J., & Li, R. (2009). Design of experiments with multiple independent variables: A resource management perspective on complete and reduced factorial designs. Psychological Methods, 14(3), 202-224. PMCID: PMC2796056  View article

Dziak, J. J., Nahum-Shani, I., & Collins, L. M. (2012). Multilevel factorial experiments for developing behavioral interventions:  Power, sample size, and resource considerations. Psychological Methods. Advance online publication. doi: 10.1037/a0026972 PMCID: PMC3351535  View abstract

Nair, V., Strecher, V., Fagerlin, A., Ubel, P., Resnicow, K., Murphy, S. A., Little, R., Chakraborty, B., & Zhang, A. (2008). Screening experiments and the use of fractional factorial designs in behavioral intervention research. American Journal of Public Health, 98, 1354-1359. PMCID: PMC2446451 View article

This article addresses the question “Is MOST really likely to produce more potent behavioral interventions in practice?” by means of an extensive statistical simulation:

Collins, L. M., Chakraborty, B., Murphy, S. A., & Strecher, V. (2009). Comparison of a phased experimental approach and a single randomized clinical trial for developing multicomponent behavioral interventions. Clinical Trials, 6(1), 5-15. PMCID: PMC2711350  View article