mohammad ahmadi deh qutbuddini; ebrahim khodai; Valiollah Farzad; ali moghadam zadeh; masoud kabiri
Abstract
The present study has been done with the purpose of investigating the dimensionality and differential item functioning of the testlet-based test of Iran's PIRLS 2011. In order to analyze the dimensionality, graded response and bi-factor item-response theory models were used with full-information maximum ...
Read More
The present study has been done with the purpose of investigating the dimensionality and differential item functioning of the testlet-based test of Iran's PIRLS 2011. In order to analyze the dimensionality, graded response and bi-factor item-response theory models were used with full-information maximum likelihood estimation method and to analyze the differential item functioning multiple-group bi-factor model of Cai et al (2011) was applied. The results of the dimensionality investigation showed that the bi-factor model is better fitted to the data than the graded response model both in Iran's total sample and in boy and girl groups. The results of testlets effect variance showed that effects of second factors on Iranian students' performance in two testlet related to literal comprehension, has caused dimensionality in Iran's PIRLS testlets. The results showed that there was no significant difference in average students' performance of the boy and girl in general latent trait of reading comprehension, but the difference between the average reading proficiency of the boy and the girl in three literal and three informational testlet in favor of girls was significant. The result of differential items functioning based on the bifactor model showed that many items have an uniform and non-uniform differential item functioning, and boys in multiple-choice items and girls in constructed response items have better performances. In general, the results showed that in Iran's PIRLS 2011 testlets, the traits related to the two literal comprehension testlets were differently perceived between boy and girl students, and these two testlet had more local item dependence among girls than boys. Also, the results indicated a difference between the performance of Iranian boy and girl students in the mixed items format test of PIRLS.
Mahmoud Negahban Salami; Valiollah Farzad; Gholamreza Sarami
Volume 4, Issue 15 , April 2014, , Pages 1-16
Abstract
Objective: The present research aims to study the factor structure, reliability, and validity of the Successful Intelligence Scale. Method: Using the multi-stage cluster sampling method, 500 (including 175 female and 325 male) subjects were selected from among public school students in Karaj. Results: ...
Read More
Objective: The present research aims to study the factor structure, reliability, and validity of the Successful Intelligence Scale. Method: Using the multi-stage cluster sampling method, 500 (including 175 female and 325 male) subjects were selected from among public school students in Karaj. Results: The exploratory factor analysis was performed using the principal component method. The results confirmed three factors of successful intelligence (i.e. analytical, creative, and practical intelligence) as well as the principal factor. Reliability of the scale items was examined using Cronbach’s alpha coefficient, and its validity was investigated using factor analysis. Internal consistency of the questionnaire was acceptable, and the Cronbach’s alpha for the subscales was between 0.74 and 0.81. Also, the confirmatory factor analysis results confirmed that the structure of the scale had an acceptable fit to the data, and that the goodness-of-fit index for the model was observed. Conclusion: The results of confirmatory factor analysis were almost close to that of studies done in the original cultural context. Validity and reliability of the scale were also close to that of previous researches. Considering the desirable psychometric property, therefore, this scale is an appropriate instrument for measuring the students’ successful intelligence.
