Strange as this may sound, though it should not as this is a blog on raising Chinese-English bilingual/biliterate children, dd#2, who is almost 10 and half, finished reading all ~ 730 pages of Harry Potter and the Goblet of Fire today!! She loved it! Yay!!!
This is the fourth book in the Harry Potter series, with Lexile Rank 880 and of 5-6th grade reading level. This is the first of the Harry Potter series of this heft. The first three books are much shorter. Some children probably read this book around 8-9 years old, but most of them probably didn’t spend as much time learning Chinese. As I explained in an earlier post, Foreign Service Institute (FSI) estimates that it takes an English speaking adult about 1.5-2 years (88 weeks) of full time instruction, studying, and practice to achieve ILR level 3 in speaking and reading. Though dd#2 is a child, I think it is a reasonable estimate that she devoted a full 1.5 to 2 years of time learning Chinese to an overall ILR ~ 3.5-4 level.
Accounting for these factors, had my dd#2 not spend this much time learning Chinese, she probably would have been able to read Harry Potter #4 at between 8 to 9 years old. The difference, of course, is one of the “price to pay” to learn Chinese to this level, at least for our family.
For nonacademic research purpose, it will be most interesting to survey families to find out the age of their child when s/he finishes reading Harry Potter and the Goblet of Fire and the Chinese ILR level that the child has achieved by that time. There are obviously many other factors involved, but may be such quick survey can help us understand the whole process better.