For all its simplicity, expectation-maximization performs incredibly well in a range of scenarios. That being said, there are some potential limitations that we need to be aware of:

• Expectation-maximization does not guarantee that we will find the globally best solution.
• We must know the number of desired clusters beforehand.
• The decision boundaries of the algorithms are linear.
• The algorithm is slow for large datasets.

Let's quickly discuss these potential caveats in a little more detail.