scuda Wrote:I wonder if there is a threshold of word coverage that gives just enough understanding to pick up all the new words entirely through context, without needing to rely on a dictionary. As a native english speaker, I picked up the vast majority of my vocabulary via reading many books as I grew up, and I never used the dictionary to learn words.
I've read a few papers on this topic, and it seems the consensus among researchers of second language acquisition is that you need about 95% coverage to guess the meanings of unfamiliar words well enough to develop your vocabulary through reading without relying heavily on dictionaries. The research is mainly about English as a foreign language, but I think it could give you a rough idea.
The caveat is that their research methods aren't sophisticated. The typical method is:
1. Take arbitrary text and leave out X% of words at random.
2. Ask native speakers to fill in the blanks and see how well they guessed the left out words.
Apparently native speakers have much deeper knowledge of the language, so they'd be much better at guessing than the average learner. 95% could be a little conservative.
There is another catch when it comes to frequency based learning, that is, they don't consider how well you know each word. For example, most of the Japanese high school students know the most frequent 1000~2000 English words. Some excellent students know 5000+ words. But probably 99% of them don't know what "What's up?" means. Of course they'd say they know "what," "is," and "up." They also know the contraction "what's." But still they fail to understand the very basic phrase. "I don't get it." is another *difficult* expression. I don't think more than 0.1% of Japanese high schoolers would understand what "You can't get away with it!" means. "We made it!" "They had pulled it off!" "I should get going." "The train pulled in the station." etc. are all difficult phrases. To put it simple, 70% Japanese word coverage would assume you understand the Japanese equivalent of "She's got knocked up. I kid you not." because all words are listed as "frequent."
Frequency lists of idioms and whanot would help a little, but still learners would get tripped up by very simple sentences like "That's the way it is." If you made a frequency based list of phrases that don't match up with literal translations, then the list would be unacceptably huge. I wouldn't be surprised if 95% coverage list of frequent anti-literal translation expressions was larger than your average dictionary for native speakers; native speakers don't need natural expressions in their dictionaries while those natural phrases are not natural to you at all.
Frequency lists can cover words pretty well, and coverage and stuff can make things look easier. But you should learn them deeper than that. I think lists are valuable to teachers, but it might be better for learners to focus more on how well they know each word than on how many words they know.
Edited: 2009-06-20, 11:52 am