You Michelle Nieva could refer to the statistical fact that Gaussian Normality is not the best measure for human learning curves, which are more probabilistic by nature.

If someone doing alternative learning system, it gives an impression that he or she was not able to get a formal education and because it's mostly due to financial constraints So this impression make this ALS group as stereotype and so a Stigma. Positive mindset and encouragement will do great and one can easily overcome this