• PDCA (Plan-Do-Check-Act):

The classic quality management cycle. Plan → Do → Check → Act. Simple and effective, like a Swiss knife. The principle was applied in the training of pilots of the US Air Force, so that they could make a more accurate and meaningful decision about the launch.

AIDA (Attention-Interest-Desire-Action):

A marketing model describing the stages of interaction with a potential client. First, we attract attention, then we arouse Interest, awaken Desire, and finally, we push to action. As they say, "the client must mature." The model is well played in the classic movie "The Americans" by the character of Alec Baldwin, who came from New York to teach not the most successful sellers of land plots in one of the offices in the United States.

HADI - (Hypothesis-Action-Data-Insights):

A product development cycle based on hypotheses. We put forward a hypothesis (💡), conduct an experiment (🏃), collect data (📊) and analyze the results (🧠). "Quickly check and learn" is the motto of this model.If you were building a startup or participated in an accelerator, then you definitely should have been introduced to this tool.The Flask Cycle (Concrete Experience-Reflective Observation-Abstract Conceptualization-Active Experiment):

• An experience-based learning model. First, we get concrete experience, then we comprehend it (Reflective Observation), form abstract concepts (Abstract Conceptualization) and apply new knowledge in practice (Active Experiment). "Learning from our mistakes" is the main principle.

So, we have four models in front of us, each of which is divided into four stages. An accident? I don't think so! Let's try to find an explanation for this phenomenon.

Hypothesis 1: The magic of the number 4

The number 4 has long been considered a symbol of integrity and order. Four cardinal directions, four seasons, four elements... Maybe it is this symbolism that subconsciously influences our perception, making four-stage models more attractive and easy to remember?

Hypothesis 2: Optimal structure

Perhaps four stages is the optimal structure for solving many problems. Too few stages, and the model will be too simplified, not taking into account all the nuances. Too many steps and the model will become cumbersome and difficult to apply in practice. The four stages are the golden mean, providing a balance between simplicity and efficiency.

Hypothesis 3: Historical context

Some researchers attribute the popularity of four-stage models to the development of scientific thought in the 20th century. At that time, a systematic approach was widely adopted, which involves the division of complex processes into simpler elements. Four-stage models fit well into this paradigm, allowing you to analyze and manage processes in stages.

Hypothesis 4: Psychology of perception

According to some psychological studies, the human brain perceives information better organized into groups of 3-4 elements. By the way, we definitely could use two more hemispheres) By the way, our heart also consists of 4 parts. Who is ready to remember?Write in the comments.This explains why many models and frameworks consist of exactly four stages. This structure helps us to remember and apply information more easily.

But what if there is some kind of "supermodel" that combines all four models – PDCA, AIDA, HADI, the Flask cycle, and so on? And this "supermodel" also consists of four stages? 🤔

Here's my joke hypothesis 🤓:

1. Awareness: Awareness of a problem or task that needs to be solved.
2. Planning: Developing an action plan to solve a problem or task.
3. Action: implementation of the plan in practice.
4. Analysis and correction: analyzing the results, receiving feedback and correcting the action plan.

This "supermodel" is universal and can be applied in different spheres of life. For example:

• Business: the company is aware of falling sales (awareness), develops a strategy to increase sales (planning), launches new marketing campaigns (action), analyzes the results and adjusts the strategy (analysis and correction).
• Marketing: the marketer sees that the advertising campaign is ineffective (awareness), plans a new campaign (planning), launches it (action), analyzes the results and optimizes the advertising materials (analysis and correction).
• Personal growth: a person realizes that he lacks skills (awareness), makes a training plan (planning), begins training (action), evaluates his progress and corrects the plan (analysis and correction).

Does the magic of the number 4 really exist?!? Four–stage models are not just an accident, but a universal tool for solving a variety of tasks. They help us structure information, plan actions, analyze results and achieve our goals.

"What other four-stage models do you know?""How do you apply these models in your work?""What do you think about the concept of a 'supermodel'?"Share it in the comments...