Three Layers of Evidence - Source: https://zettelkasten.de/posts/layers-of-evidence/ - by Sascha
In a Zettelkasten – if done correctly – there will emerge layers of evidence. These layers represent the necessary processing steps from data to knowledge.
The three layers of evidence...
Data description and patterns.
Interpretation of descriptions and patterns.
Synthesis of patterns, descriptions and interpretation.
The first layer of evidence is a description of data. I will call that the phenomenological layer. This description is limited to meaningful patterns in the data – or a meaningful lack of patterns, which could be considered as a pattern in itself. If you read an empirical study, for example, you come up with patterns that you can observe and the conditions on which the patterns can be observed.
The next layer of evidence is the interpretation of data patterns. The phenomenological layer meant you describe what you saw. Here, you interpret why you saw it.
Now the concept of causality can come into play.
The third and last layer of evidence is the level of synthesis. This layer is to the second what the second is to the first. You take the entities as building blocks for the bigger picture. You string together hypothesis, theories, models and more create something that is useful, interesting, entertaining and what not.
Examples of the three levels of evidence...
Phenomenon:Â Serotonin is part of the physiological substance that constitutes status.(6)Â Cooperations and alliances are integral part of status.(7)
Interpretation:Â Serotonin is a regulator of negative emotion and emotion in general can be optimized via dominance and cooperation.
The broader picture: You cannot have optimized serotonin while being weak (lack of dominance) or being alone and only dominant (lack of altruistic behavior). Depression as a side effect of deregulated serotonin can only be considered a physiological disorder if there is no disorder in the rest of one’s life, like being isolated or lacking competitiveness. Therefore, self-development depends partly on the correct (factually and morally) application of status principles in your life. Computer game addiction is an example of pathology and developing your (creative knowledge work) business to support your loved ones is an example of healthy behavior.
Phenomenon:Â Feature Requests are truly that. Users normally express their wishes in the form of a specific app behavior. E.g.: The Archive should allow for multiple tabs. The Archive should allow for multiple windows.
Interpretation: Feature Requests depend on the individual representation of the problem. They are the concrete manifestation of more abstract problem. User say “I want multiple tabs and multiple windows!” rather than “I have difficulty to handle complex projects with a lot of notes and layers. I think that multiple tabs and windows would help me.”
Practical Application:Â Ask for the specific use cases. Ask for the perceived problem and try to get the actual problem and not the individual representation of the problem that manifests in a specific feature request. You can decide which steps you need to take much better once you understand the problem in this context.
Your notes should always reflect different layers of evidence. They build on each other, not only in an abstract way. Either a note belongs to one of the layers, or it itself is divided according to those three layers. In the first case, it only contains phenomena, interpretations, or integrations.
The notes are then linked to each other: An interpretation note links to a phenomenon note as reference, the integration notes link to the interpretation notes. In the second case, the note contains a description of phenomena at the top, followed up with the interpretation of the phenomena and the integration into the bigger picture.
It is not always possible to be that clean. But take it as an ideal to strive for. It is also a tool for thinking which is not an incidence. The Zettelkasten Method is the concrete manifestation of the abstract principles of good thinking practices and knowledge creation.
The principle of layered evidence is either correctly applied or violated. You can read and learn from both. Sometimes, authors don’t care if they reference secondary or primary literature. If you want to work correctly, you’ll have to deal with this behavior. If you read something interesting but the facts are not derived from primary literature, you can’t trust those facts. Always – at least at random – check if the primary literature is used correctly. I fell flat on my face after I first discovered how widespread mishandled and misused primary resources are. There are a lot of people who want to sound scientific as a means of marketing.
So, always check the primary literature if there is any. Take texts that cite only secondary literature with a great heap of salt.
Your notes should always reflect different layers of evidence. They build on each other, not only in an abstract way. Either a note belongs to one of the layers, or it itself is divided according to those three layers. In the first case, it only contains phenomena, interpretations, or integrations.