How do training methods impact subsequent task performance by a trainee? Which combinations of training methods are more effective for training different types of tasks? Decisions on how to efficiently train a workforce require an understanding of the factors that impact training effectiveness, cost effectiveness, need for periodic retraining, and training transfer. This paper describes a research project that identifies relationships between training methods, task characteristics, and outcome measures that can provide an evidence base to guide training design decisions. The focus is on training methods that promote retention and transfer of the complex cognitive skills involved in technology related military task domains. During the initial phase of the research we conducted a broad review of the published research literature on training effectiveness and training methods. Based on this review an organizing framework was developed to consider training methods within the context of training design decisions. Training method specific meta-analyses were conducted to generate training effectiveness estimates based on analysis of primary studies. Given the emphasis on complex cognitive tasks and training transfer, six methods associated with managing trainee workload and/or promoting transfer were selected for the initial phase of the meta-analysis research. We discuss meta-analysis results for two training methods, worked examples and exploratory learning.