Validation Accuracy is changing when the same classifier is trained on the same data

Hello. I am using ensemble classifiers in the Matlab Classification Learner. The problem is that I am getting different accuracies when training the same classifier (Bagged Trees) on the same data.

Answer 1

[Walter Roberson]

Most of the classifiers include random initialization. To repeat the same accuracy with the same classifier on the same data, set the random number seed each time, using rng()

[Mortada Haidar]

Ok I see. But then how can I assess the performance of my model? Validation accuracy is changing drastically when changing the seed..

[Walter Roberson]

In such a case you have to assume that there is a lot of over-fitting. Reduce the size of your training set and increase the size of your test set.