Chapter 1 the study of collocations

v) Length of T-Units 
 
 
After the T-Units per each essay were calculated, the average length for 
the T-Units in each essay was estimated by dividing the total number of words 
in each essay by the number of T-Units in that essay (see Larsen-Freeman 1978), 
e.g. an essay with 186 words and 25 T-Units had 7.44 as the average length of a 
T-Unit.  This was a complexity measure. 
 
vi) Error Free T-Units 
 
 
The number of error-free T-Units per each essay was also calculated as 
an accuracy measure.  Only T-Units that were free from grammatical, syntactic, 
lexical, spelling and punctuation errors were counted as Error-Free T-Units (see 
Larsen-Freeman 1978).  Inter-rater reliability on a randomly sampled sub-set of 
the data (15 essays) was also obtained from two other raters, and was at 97%.  
Each of the raters was given the same sample of essays and instructions for 
counting the Error-Free T-Units in each essay (see Appendix K).  A short 
training session was given by the researcher on two other essays.  After the 
 
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measurement, the number of Error-Free T-Units marked by the raters and the 
researcher was compared, and the inter-rater reliability (97%) was considered 
sufficient for the Error-Free T-Units measurement.