Introduction
The Knowledge Spiral Model was proposed by Ikujiro Nonaka and Hirotaka Takeuchi in 1995. It specifically analyzes how tacit and explicit knowledge interact through four conversion processes: socialization (tacit to tacit), externalization (tacit to explicit), combination (explicit to explicit), and internalization (explicit to tacit).
Nonaka’s model argues that all knowledge is transferrable under the right conditions. The model is called the Knowledge Spiral because Nonaka viewed the transfer of knowledge as a continuous learning process. In this process, the learner comes to deeper and deeper levels of understanding on a particular topic as they move around the cycle.

Case Study
Let’s use an example to illustrate the transfer of tacit and explicit knowledge within the context of the Knowledge Spiral Model.
You are a new employee at your organization and a friendly colleague becomes your mentor. You are learning information from this person through observation and interaction. Through a process of socialization, they are transferring their experience (tacit knowledge) to you, which results in you acquiring new skills.
You have a question about why your mentor does something in a particular way. They try to pass this knowledge onto you through a conversation, which means they are transferring knowledge to you through a process of externalization. They are making tacit knowledge explicit by telling you stories of their experiences, using metaphor or analogies to explain concepts, and through dialog.
You still have questions about how to enter data into your computer and your mentor is out for the day. They ask you to e-mail the questions and they send you back step-by-step answers for data entry. Now you are transferring knowledge through the combination process. Your mentor has given you relevant knowledge, edited it, and processed it to make is usable.
You have been at the job for a year and notice how much your productivity has increased. You now know the processes and have found ways to improve how you do things. You have internalized knowledge; in other words, you have transformed explicit knowledge into tacit knowledge.
Summary of the Models Presented
The knowledge management models presented provide theory to inform your practice. While these models have similar elements, they also differ from each other. This is an accurate reflection of knowledge management: there are basic pillars that comprise the concept (like the involvement of people, technology, and processes), but there can also be variation within the development and execution of the idea.
This variation mimics the development of knowledge management within your organization. You will need to have a solid foundation based on the principles of knowledge management, but you will also need to tailor your program to suit the needs of your organization.