This study looks at the effects of changing the deletion direction and ratio on the validity and reliability of the C-test. For this purpose, a cluster sampling procedure was used to select 324 English students with different levels of proficiency. The subjects were then randomly assigned to three experimental groups. Each group took a TOEFL test and a C-test version. The three C-test versions were all based on the same texts. Immediately after completing the C-test, subjects received a ten-item questionnaire about issues such as face validity, suitability, and possible functions of the C-test. The findings indicated that changing the deletion ratio from 2 to 3 can result in an easier C-test with a higher discrimination power and a better criterion-related validity. On the other hand, changing the deletion direction (from right to left) can result in a more difficult C-test with a lower discrimination power and a worse concurrent validity –a C-test which might be a completely different test that measures a different construct. However, the changes to the deletion technique probably do not result in any changes to the reliability.
Sahragard,R. , Rahimian,J. and Rahmani Anaraki,R. (2008). The effects of changing the deletion direction and deletion ratio on the validity and reliability of the C-test. Teaching English Language, 3(1), 23-52. doi: 10.22132/tel.2008.128580
MLA
Sahragard,R. , , Rahimian,J. , and Rahmani Anaraki,R. . "The effects of changing the deletion direction and deletion ratio on the validity and reliability of the C-test", Teaching English Language, 3, 1, 2008, 23-52. doi: 10.22132/tel.2008.128580
HARVARD
Sahragard R., Rahimian J., Rahmani Anaraki R. (2008). 'The effects of changing the deletion direction and deletion ratio on the validity and reliability of the C-test', Teaching English Language, 3(1), pp. 23-52. doi: 10.22132/tel.2008.128580
CHICAGO
R. Sahragard, J. Rahimian and R. Rahmani Anaraki, "The effects of changing the deletion direction and deletion ratio on the validity and reliability of the C-test," Teaching English Language, 3 1 (2008): 23-52, doi: 10.22132/tel.2008.128580
VANCOUVER
Sahragard R., Rahimian J., Rahmani Anaraki R. The effects of changing the deletion direction and deletion ratio on the validity and reliability of the C-test. TEL, 2008; 3(1): 23-52. doi: 10.22132/tel.2008.128580
