The learning environment is a key and important component of the learning process. Keep in mind that learning is only half of the distance educational process. How we learn and where we learn is very can play a big part in how effective we are in our education. The definition of synchronous implies that we are synchronized with the instructor and the other students. We are bound within the same time continuum. In other words, you are real time with the process. For example, if I were instructing you how to land an airplane in an emergency situation, you would not want me to do this with email. The immediacy of the situation would require that I have prompt, direct communication with no delays. My responses would require immediate assessment and feedback. There would be no opportunity to ponder my thoughts and delay my interaction.
Asynchronous, simply means – not synchronous. We could can communicate with as much time delay that is needed. The demand of being present at a specific time to learn the material and the pace of interaction has fallen out of the learning equation. Asynchronous could work fine if there is no need for immediate feedback. For example, if I want to learn how to change a tire, I can learn about it at my own pace and not need to depend on anyone else to immediately provide insights or guidance. On the other hand if I want to learn how to make a casserole, the timing might be a very important factor (take it our of the oven now).
What is better for fostering online learning is a matter of preference and circumstances. If is a function of the content that is being taught and the importance of getting immediate feedback. It is like asking the question, what is better a fork or a spoon when eating a meal. The answer is – it depends on what you are eating. The same applies here – it depends on what you are trying to learn. Watching a video on how to replace a water heater might be sufficient to get the job done. Watching the video and then having a synchronous session with experts and others who have replaced a water heater might yield a better outcome. The blended approach could work fine. It does not have to be one or the other.