We all carry experiences in our head and these concepts are referred to as mental models. Everyone interprets an experience a little differently based on how we perceived the experience or relate it to previous experiences. As we experience more we refine our mental models and build new ones.
In order to get our ideas out we must find and make connections. This is called synthesis. It is the idea of making sense of something abstract. At this point it isn't important to be accurate. We want to get everything out so that we can understand the 'system' and give the abstract idea tangible form. Once the idea is externalized through a sketch, drawing, painting, writing, etc., the idea becomes real and it can be discussed, critiqued or finally synthesized. You finish with a tangible thing to work with. From here you can choose to keep it or reject it. It isn't easy and not every idea will work. Iteration is important in order to find the right idea.
Synthesis forces us to make connections with completely unrelated pieces of information. We make connections by reducing, organizing or prioritizing the information. Problems can become too large far too easily and often times there is too much information to make sense of. That is why it becomes important to document a problem and find a space to externalize everything captured so that we don't forget things and can understand the problem as a whole at one time. This is why designers love whiteboards and post-its.
We can better understand how synthesis works by looking at John Kolko's idea of abductive reasoning (Exposing the Magic of Design). Abduction is the step of adopting a hypothesis as being suggested by the facts as a form of inference. In simple terms it is the act of connecting two seemingly unrelated ideas and combining them to make a completely new idea. It is the process of creating a 'what if' or best guess.
The Idea: Both A and B are possible, but are unrelated. If C is happening in A, I am able to abduct that C is possible in B.
Example: I travel in my car and I live in my home. If I can drive my car, I am able to abduct that it is possible to drive my house.
There are four funnels or guidelines to think about when designing a flawless user experience. Perfection is in the details.
Predictability is about making something known in advance by inference or special knowledge. Provide advance warnings of consequences or create an affordance to suggest use. Be consistent in behavior and appearance directly shows the structure of the task or process. Be transparent about complexity.
Desirability is about placing value on something even without previous knowledge. Be descriptive and don't leave the using hanging. Balance the structure and freedom. Provide necessary support for new users without impeding experts. Let your users make mistakes or go back to a previous state. Give users a call to action or clear goal.
Utility is about giving the user only what they need. Many misinterpret what this actually means. Let your user focus on one thing at a time but also don't assume users are dumb. Show relevant information and minimize needed translation with visuals. Provider increases levels of detail when the user needs it. It can help prevent errors and reduce the brain power needed.
Predictability is about satisfying needs and wants. Give the user things that are useful and support them with proactive feedback and resources. Educate yourself on best practices and apply as much as possible. Don't be afraid to push the boundaries and be creative however.