06:25 Sep 1, 2009 

Thanks! It helped a lot!

05:45 Sep 1, 2009 

With this context, I think it is clear the survey is about teachers "in" the school and it is a comparison between what each individual teacher can contribute to the students' learning and what the school as an institution does. So, I think my translation or Cristina's are OK.

05:37 Sep 1, 2009 

Okay here I go:
Schooling accounts for about 20% of the variance in student achievement. However, in my synthesis of the research, I also found that about 67% of this effect is due to the effect of individual teachers. That is, about 13% of variance in student achievement in a given subject area is due to what the teacher does and about 7% is due to what the school does

05:29 Sep 1, 2009 

More context is necessary to be certain.

05:13 Sep 1, 2009 

I was thinking in that translation too. But my problem is that I got confused when I looked for a similar concept "individual classes" that means "clases particulares". I wasn't sure if this term is used too like "profesores particulares", because that would be sth completely different. But if you assure me that "cada maestro or profesor en particular" is the only meaning, I will be glad forever.

Thanks everyone!