TY - JOUR ID - 128580 TI - The effects of changing the deletion direction and deletion ratio on the validity and reliability of the C-test JO - Teaching English Language JA - TEL LA - en SN - 2538-5488 AU - Sahragard, Rahman AU - Rahimian, Jalal AU - Rahmani Anaraki, Reza AD - Shiraz University Y1 - 2008 PY - 2008 VL - 3 IS - 1 SP - 23 EP - 52 KW - C-test KW - deletion direction KW - deletion ratio KW - Validity KW - Reliability DO - 10.22132/tel.2008.128580 N2 -  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. UR - http://www.teljournal.org/article_128580.html L1 - http://www.teljournal.org/article_128580_355360f11ac6e20eb32cc6a2d676cf68.pdf ER -