"HASSOU-HOU" is a book by Jiro Kawakita. He is an anthropologist and the inventor of the KJ method. He explained the process to make a theory from information gathered by fieldwork. He proposed the W-shaped problem-solving model.

Fig: Jiro Kawakita's W-shaped problem-solving model

Let's divide the model into steps in the same way.

Jiro Kawakita said that field science is necessary before the experimental science. From ❶ to ❺ corresponds to field science. From ❻ to ❾ corresponds to experimental science. The process of experimental science is to verify the hypothesis by experiment. For the process, we need to make a hypothesis first. The hypothesis is an idea of a model that explains the observation. Jiro Kawita called the process of creating this idea as field science and invented exploration method (*9) and KJ methods as its methodology.

In the W-shaped problem-solving model, we first gather information by ❸ observation. Then, we organize the information by the KJ method, and hypotheses come up in the process. It is ❹. The KJ method is similar to James Webb Young's material processing phase. In his model, the boundary between "plowing phase" where information is gathered and processed, and "seedling phase" which comes up with a hypothesis is not clear. He explained as if the idea sprout during plowing.

After we get a hypothesis, we carry experimental science. Experiment verifies whether the hypothesis is correct or not. In other words, think what kind of experiment can verify the hypothesis, experiment, observe the results of the experiment, and verify that the hypothesis is correct or not. If the experiment results deny the hypothesis, we need to correct the hypothesis. We revise the hypothesis so that the hypothesis correctly explains the observation. This experimental science corresponds to the "growing phase."

Footnote (*9):

In the process of teaching the KJ method, Kawakita Jiro thought that he should dig deeper into the method of exploration. It is the previous stage of the KJ method. And then he published "CHI NO TANKEN-GAKU" (Exploration-ology of knowledge).