Opportunities, Challenges, and Future Directions

This chapter contributes many suggestions for future research directions. These are grouped by category and sub-category, and based on gaps the authors noticed in previous work or on original ideas inspired by synthesizing the methods reviewed in the survey. Ideas which build on existing methods are suggested as well as research directions that combine multiple methods from the survey. Additional project proposals combine methods in this book with concepts from outside the field, and other original ideas are presented as well. At the end of this chapter we offer concluding thoughts.