Errors (IELTS writing task 2)

Submitted by Ren Shres on Tue, 06/17/2014 - 13:19

I recently submitted an essy. And, when my essay was reviewed by 'essay e-rater' I had these errors in my essay-
flaws:
No. of Different Words: 156/200
Avg. Sentence Length: 16.412/21.0

My questions:
-what do these errors mean?
-do 'numbers of different words and avg. sentence length' can increase or decrease my IELTS score in real test?