Recently, Rebecca J. Stones asked, Does it take “about 50 exposures for most words to be retained in long term memory”? The question was about a claim by Terry Waltz that classroom learners need a few dozen exposures to new words before they can retain them. In one source, Terry Waltz had written that she
aim[s] for 70-80 exposures in novel contexts during the first day of presentation, (...).
However, other researchers (Fooziyeh Rasouli and Khadijeh Jafari, "A Deeper Understanding of L2 Vocabulary Learning and Teaching: A Review Study", 2016; see one of my previous answers) had found that
a typical learner should meet a word about 8 to 10 times to obtain full word knowledge.
This is a significantly lower number and much too low according to Terry Waltz, even for target languages that are close to the learner's native language.
Terry Waltz uses a teaching method known as TPRS / Teaching Proficiency through Reading and Storytelling, which focuses much more heavily on comprehensible input than many other teaching methods. This leads me to the question whether the higher number of required exposures is related to the teaching method being employed. Please note that I am specifically interested in teaching methods, not in self-learning, which is a different matter. Responses based on research would be appreciated.