Ren,

I think most schools (independent of states) use Lexile scale for LOG. The only thing is that they usually under/overestimate the younger kids (especially kinder and 1st grade teachers). It has oberver variation and someone may score higher than the other on the same kid depending on what they ask the kid to read. My DD9 got higher lexile scale in 2nd grade than 4th but she is progressing and I attributed that to technical error.