| The aim of this study is to investigate the effect of gender differences of 15-year-old students on scientific literacy and their impacts on students' motivation to pursue science education and careers (Future-oriented Science Motivation) in Hong Kong.;The data for this study was collected from the Program for International Student Assessment in Hong Kong (HKPISA). It was carried out in 2006. A total of 4,645 students were randomly selected from 146 secondary schools including government, aided and private schools by two-stage stratified sampling method for the assessment.;HKPISA 2006, like most of other large-scale international assessments, presents its assessment frameworks in multidimensional subscales. To fulfill the requirements of this multidimensional assessment framework, this study deployed new approaches to model and investigate gender differences in cognitive and affective latent traits of scientific literacy by using multidimensional differential item functioning (MDIF) and multilevel mediation (MLM). Compared with mean score difference t-test, MDIF improves the precision of each subscales measure at item level and the gender differences in science performance can be accurately estimated. In the light of Eccles et al (1983) Expectancy-value Model of Achievement-related Choices (Eccles' Model), MLM examines the pattern of gender effects on Future-oriented Science Motivation mediated through cognitive and affective factors.;As for MLM investigation, Single-Group Confirmatory Factor Analysis (Single-Group CFA) was used to confirm the applicability and validity of six affective factors which was, originally prepared by OECD. These six factors are Science Self-concept, Personal Value of Science, Interest in Science Learning, Enjoyment of Science Learning, Instrumental Motivation to Learn Science and Future-oriented Science Motivation. Then, Multiple Group CFA was used to verify measurement invariance of these factors across gender groups.;The results of Single-Group CFA confirmed that five out of the six affective factors except Interest in Science Learning had strong psychometric properties in the context of Hong Kong. Multiple-group CFA results also confirmed measurement invariance of these factors across gender groups.;The findings of this study suggest that 15-year-old school boys consistently outperformed girls in most of the cognitive dimensions except identifying scientific issues. Similarly, boys have higher affective learning outcomes than girls. The effect sizes of gender differences in affective learning outcomes are relatively larger than that of cognitive one.;The MLM study reveals that gender effects on Future-oriented Science Motivation mediate through affective factors including Science Self-concept, Enjoyment of Science Learning, Interest in Science Learning, Instrumental Motivation to Learn Science and Personal Value of Science. Girls are significantly affected by the negative impacts of these mediating factors and thus Future-oriented Science Motivation. The MLM results were consistent with the predications by Eccles' Model.;Overall, the CFA and MLM results provide strong support for cross-cultural validity of Eccles' Model. In light of our findings, recommendations to reduce the gender differences in science achievement and Future-oriented Science Motivation are made for science education participants, teachers, parents, curriculum leaders, examination bodies and policy makers. |
