Opportunity cost is a term from economics. It refers to the loss of other alternatives when one alternative is chosen.
In every lesson you plan and teach there are numerous options. They are not all equal in terms of their learning value, that much we can agree on. I'd like to question the value of vocab learning websites/apps.
Now, I must make it clear that isolated word vocab learning can have a place and apps, from what teachers write, suit some pupils well. Teachers report productive lessons and homework using Quizlet and Memrise, for example. One teacher wrote on social media that almost all the homework she sets is based on Quizlet. Quizlet Live (where pupils can compete with each other in class to win vocab games) is getting good reports too.
If you are not familiar with Quizlet or need a reminder here is an example for advanced students doing A-level French.Have a quick look and try the Gravity game.
Perhaps because of my own methodological journey which began with the TL direct method question-answer approach of the late 1960s, I have always been a bit wary of vocabulary learning from lists. Similarly, vocab apps have never appealed to me and I can only imagine using them rarely in the classroom or for homework. I've only recently thought a bit more about what my aversion to them is. What I've been reading gives me some evidence to support my instinctive wariness about isolated word learning.
We know from brain research that words are better retained in memory when repetition and "deeper processing" is involved in learning them. For more on this see my recent blog here. Words will be better remembered, for example, if they are heard or read in context (surrounded by other words), associated with pictures, the context in which they were learned, with the aid of rhymes and alliteration, or when associated with a powerful emotional experience.
Now Quizlet involves a game element (e.g. Gravity), enables the words to be heard as well as seen, and involves repetition and a competitive element. All of these help with retention. On the other hand Quizlet is quite undemanding in terms of deeper processing. Isolated word recognition is, after all, pretty easy, which is why pupils find it so approachable and, to a point, enjoyable. (We cannot underestimate the motivational factor here.)
So back to opportunity cost. What could pupils be doing with their hugely limited time instead of isolated word practice? They could be listening to or reading whole sentences or short paragraphs incorporating the target vocabulary. They would simultaneously be acquiring the ability to separate out words in the sound stream (the main challenge of listening). They could be engaging in oral interactions with partners or the teacher which include the target vocabulary. They could be writing sentences or paragraphs using the same vocabulary. All of these tasks involved some communication and language skills at the sentence and paragraph level. To me this makes more sense than drilling individual words and will,probably produce better long-term retention. If you want to go down the "comprehension hypothesis" (Krashen) route, you might also argue that young humans never acquire vocabulary by learning individual words consciously, they pick them up by hearing them in context.
Let me emphasise that I'm not arguing against teaching isolated words per se. I would advocate doing this at the introductory stage with near-beginners and low-intermediate pupils and even recommend it for revision for assessments, for example. But it would occupy a small fraction of the total teaching time. Last minute cramming is good for short term tests, but poor for long-term retention.
I just wonder if the temptation to use vocab apps because they may be quite fun and are undemanding comes at a cost.
What do you think?