There initial statement is "A theory is a contingent statement of what causes what and why". People when building a theory usually take three steps, they being:
- Carefully observe, describe and measure the phenomena.
- Group observations into categories, then
- Develop a theory that explains the attributes and how they lead to the results
Working with theories is an iterative process in which the person keeps testing. The theory is used to predict the expected result in various situations and typically they will encounter anomalies. It is these anomalies which their theory did not predict and do happen that are used to temper the theory. It is in the discovery of these anomalies that is pivotal in the process of building and improving the theory. As the research is carried out and the categorisation is tuned with any anomalies the theory starts to stablise.
The important part is the distinction between anomalies that a theory cannot account for and exceptions that a theory can account for. a theory with a good circumstance-based categorisation scheme and a causal underpinning explains the actions a practitioner can take to change the circumstances or to account for the forces that act upon them.
Further information can be found in "The Innovator's Solution, chapter 1"