Welcome back. In the first part of our course, we held the organizations requirements and constraints at bay while we drilled down on the stakeholder essentials. We were concerned that we might filter stakeholder needs through our very powerful organizational lens, and never get to break through thinking otherwise. But now as we prepare to move into testing and ask the what wows and what works questions, we need to bring the organizations requirements back in. We transition from idea generation into testing by first examining which of the portfolio of concepts we've created might achieve what we call the wow zone. The intersection of what stakeholders want, but the organization can sustainably offer. As we prepare to enter this land of experimentation, we first surface the critical assumptions behind why we believe that our concept should be successful for both the stakeholder and the organization. We'll then create visual prototypes that allow us to test our critical assumptions in a way that makes them feel real to the people we're seeking feedback from. Now the truth is, you'll never have enough time, energy, and money to explore all of the concepts you've identified. So, we need to make some tough choices between high-potential projects. Some of them will need to be set aside at least for now. To understand the power of assumptions, this week we'll head back to Washington DC, to yet another very large federal agency, Health & Human Services. Where you'll see that even in an agency of 80,000-plus people, everyone can make a difference if they learn to harness the power of design thinking in general, and assumption testing in particular. Our health and human services story will focus on the experiences of a young quality control officer at an Apache Indian reservation in Arizona as she tests ideas for reducing long wait times at the local hospital she works at. After that, assumptions now in hand, we're ready to move into prototyping to see what this looks like in action. We'll visit some of the most remote regions of Mexico, to look at the work of an influential NGO MasAgro. MasAgro is a partnership between the Mexican government and agricultural groups that work with local farming communities to try and bridge the gap between farmers and research scientists, and encourage the adoption of sustainable, modern, agricultural methods. But subsistence farmers' entire livelihoods can rely on the success of each year's crop, and so they are very understandably reluctant to risk abandoning their traditional tried and true methods for the new ones, even if the new ones are aimed at raising their income. MasAgro's approach is to use respected community leaders, and local hubs to create prototypes that are literally field experiments, to figure out what performs best under each location's unique conditions. In the process, they demonstrate what works to skeptical farmers. We'll also return to visit our old friend at Monash University Medical Center to look at some of their experiments in action. Then having completed our tour through the four questions, we'll do a bit of reviewing of a territory we've covered. We'll end with some advice and some suggested actions for impact as you prepare to put to use all of the practices and tools we've talked about. This, our final module, has an especially full agenda, so I think we'd better get started.