I’ve learned that when choosing a number of clusters, you should look for an elbow point for different values of K. I’ve plotted the values of withinss for values of k from 1 to 10, but I’m not seeing a clear elbow. What do you do in a case like this?
Answer
Wrong method?
Maybe you are using the wrong algorithm for your problem.
Wrong preprocessing?
K-means is highly sensitive to preprocessing. If one attribute is on a much larger scale than the others, it will dominate the output. Your output will then be effectively 1-dimensional
Visualize results
Whatever you do, you need to validate your results by something other than starting at a number such as SSQ. Instead, consider visualization.
Visualization may also tell you that maybe there is only a single cluster in your data.
Attribution
Source : Link , Question Author : Jeremy , Answer Author : Has QUIT–Anony-Mousse