One advantage of e-learning is that the delivered messages & information provided is 100% consistent every time the "on switch" is pushed vs instructor provided.

However, interaction with a live well informed human is also critical to provide better understanding, clarifactions, answer questions, tranlate soem of the "Americanese" or other local terminology that finds it way into presentations like the use of cushion & soild tires or tyres interchangeably.

Just my 2.5 cents worth