Intro; Preface; The Chapters in This Book; How to Use This Book; Contents; Using the Multiphase Optimization Strategy (MOST) to Develop an Optimized Online STI Preventive Intervention Aimed at College Students: Description of Conceptual Model and Iterative Approach to Optimization; 1 Introduction; 1.1 The Current Chapter; 2 The Conceptual Model of the Intersection of Alcohol Use and Sexual Behaviors; 2.1 Overview; 2.2 Intervention Components; 2.2.1 Outcome Expectancies; 2.2.2 Descriptive Norms and Injunctive Norms; 2.2.3 Perceived Benefits; 2.2.4 Self-Efficacy to Use PBS

2.3 Pathways from the Intervention Components to Alcohol-Related Sexual Risk Behaviors and STIs2.4 Potential Moderators; 2.4.1 Gender; 2.4.2 Race/Ethnicity; 2.4.3 Other Individual-Level; 2.4.4 Environmental; 3 Optimizing itMatters; 3.1 Overview of the Iterative Approach to Optimization; 3.2 Criteria for Determining Whether a Component Has an Empirically Detectable Effect; 3.3 Design of the Optimization Trials; 3.4 Subjects and Measures; 3.4.1 Subjects; 3.4.2 Outcome Measures; 3.5 Revision of Components; 3.6 Secondary Analysis of Data from the Optimization Trials; 4 Evaluating itMatters

5 Discussion5.1 The Conceptual Model; 5.2 The Iterative Approach to Optimization; References; Implementing Factorial Experiments in Real-World Settings: Lessons Learned While Engineering an Optimized Smoking Cessation Treatment; 1 Introduction; 2 Tobacco Treatment Optimization Trials; 3 Factor Selection; 3.1 Selection of Robust Intervention Components with Appropriate Comparison Levels; 3.2 Common Treatments or Constant Components; 3.3 Similarity of the Intervention Components; 4 Factor Integration and Implementation; 5 Implementing Factors with Fidelity; 5.1 Protocols; 5.2 Staff Training

5.3 Rigorous Systems5.4 Fidelity Checks; 6 Randomization; 7 Data Collection; 8 The Participant Perspective; 9 Reporting Results; 10 Conclusions; References; Multilevel Factorial Designs in Intervention Development; 1 Introduction; 2 Classes of Multilevel Factorial Designs; 2.1 Within-PEC Factorials; 2.2 Between-PEC Factorials; 2.3 Hybrid-PEC Factorials; 2.4 Full-EIC Factorials; 2.5 Partial-EIC Factorials; 3 Discussion; 3.1 Accommodating Cluster-by-Treatment Interactions; 3.2 Extensions to Sequential Randomizations; A.1 Appendix 1: Details Concerning Power Calculations

B.1 Appendix 2: Sample R and SAS Code for Calculating PowerC.1 Appendix 3: SAS Code for Hybrid-PEC Designs; References; Experimental Designs for Research on Adaptive Interventions: Singly and Sequentially Randomized Trials; 1 Introduction; 2 Adaptive Interventions; 2.1 An Example Adaptive Intervention: Social Skills Intervention in a School Setting for Children with Autism Spectrum Disorder; 3 Unanswered Questions When Building an Optimized Adaptive Intervention; 4 Experimental Designs for Building Effective Adaptive Interventions; 4.1 Example 1: A Two-Arm SRT