Understanding Cluster Analysis from Scratch: K-Means Method ①

 In the field of data analysis, a major theme is how to group vast amounts of data and extract useful patterns.

Among various methods, the k-means method is a simple yet powerful clustering technique widely used in many fields. 

This article will explain what the k-means method is, where it is used, and the benefits of learning this technique.

1. What is the K-Means Method?

The k-means method is one type of clustering technique, an algorithm for dividing data with similar properties into “clusters” (groups). It divides individual data points within a dataset into a predetermined “k” number of clusters, aiming to increase the similarity of data within the same cluster and clarify the differences between different clusters.

- Simple and Intuitive: The algorithm is very easy to understand and implement, making it accessible to both beginners and professionals.

- High Computational Efficiency: It operates relatively quickly even with large datasets, making it practical in various fields such as marketing, image analysis, and sensor data analysis.

- Fundamental to Clustering: Understanding the k-means method is extremely important as a stepping stone to other more complex clustering techniques.

2. Where is it Used?

The k-means method, due to its simplicity and flexibility, is applicable to a variety of real-world problems. Here are some specific examples:

- Customer Segmentation: Extracting groups with similar trends based on customer purchase history and behavior patterns. This is useful for optimising marketing strategies and implementing targeted advertising.

- Image Segmentation: Grouping images on a pixel-by-pixel basis, used as a pre-processing step in image processing to extract backgrounds and objects.

- Patient Data Classification: Clustering multi-dimensional data such as symptoms, genetic information, and test results to identify patient risk groups. This is used to assist diagnosis and develop treatment strategies.

- Anomaly Detection: Learning normal patterns from a large amount of sensor data and detecting outlier data points. This plays an important role in manufacturing and infrastructure monitoring.

In these scenarios, the k-means method provides a simple approach to grouping “similar things together”, allowing for a clear understanding of data patterns and promoting decision-making in business and research.

3. What are the Benefits of Learning it?

By learning the k-means method, you can enjoy many benefits in the practical application of data analysis and machine learning:

- Improved Skills in Understanding Data Essence: You can intuitively grasp hidden patterns and groups within a dataset, providing practice in deeply understanding the nature of the data. This makes subsequent analysis and model building more effective.

- Acquisition of Basic Clustering Techniques: The k-means method is the foundation of clustering. Firmly understanding this will make it easier to apply more complex algorithms (e.g., hierarchical clustering, DBSCAN).

- Practical Application in Projects: As a simple algorithm used in many practical situations, it is a technique where you can easily experience results in a short period of time. For example, it can be applied to customer analysis in the marketing department or image processing projects.

- Acquisition of Basic Concepts of Computer Science: Learning basic concepts such as distance calculation, iterative processing, and convergence determination will deepen your understanding of algorithmic logical thinking and optimisation techniques.

In Conclusion

The k-means method is a simple yet practical clustering technique that is active in a wide range of fields, including business, image analysis, healthcare, and IoT. Its basic idea is to "group similar data together", and it is attractive for its intuitive ease of understanding and high computational performance.

Furthermore, learning the k-means method is very meaningful as a step towards further advanced data analysis techniques, as well as fostering a basic ability to understand data patterns and characteristics. First, try the k-means algorithm and experience its effectiveness and applicability. This will surely level up your data science skills.

If you want to learn the k-means method, we recommend this book (click here for access).