Detecting DIF of a Pictorial Vocabulary Size Test: A Social-Cultural Inquiry

• Main Authors: Cheng, Hsun, 鄭郇
• Other Authors: Tseng, Wen-Ta
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/kmm8cm

碩士 === 國立臺灣師範大學 === 英語學系 === 103 === The present study aims to investigate the differential item functioning (DIF) of cultural capital on Pictorial Vocabulary Size Test (PVST) for junior high school students. This study also identifies the reasons account for such DIF phenomena, and ensures the fairness of PVST. It is hoped that an appropriate vocabulary size test for junior high school teachers is provided. Participants were 1,393 junior high school students from different urban and rural areas of Taiwan. DIF analyses were conducted to identify test items that account for the DIF phenomena. DIFAS, Winsteps, and RUMM are three statistical programs adopted to identify large and moderate DIF items. Six participants were selected as the interviewees to describe their thinking process during the test. The study also discussed possible causes of DIF. The analyses of district DIF on PVST indicated that the average percentage of items displaying district DIF was low, at about 5.6%. There appeared to be a correlation among district DIF, different cultural capital, and item characteristics. When the pictures were related to particular life experiences and specific cultural capital groups, district DIF was demonstrated. It is suggested that PVST item writers should avoid the design of items associated with particular life settings. Therefore, the use of pictures in the test should avoid specific objects, places, scenes, life experiences and so on, so as to maintain the quality of test items and to ensure the fairness of the test. Keywords: vocabulary size, fairness, cultural capital, DIF