This study examines the effect of portfolio assessment on Jordanian EFL tenth grade learners' overall writing performance and their performance on the sub-skills of focus, development, organization, conventions and word choice. The study is quasi-experimental in which an experimental group and a control group of 20 students each were purposefully drawn from tenth grade classes at the public schools for girls in the North-Eastern Badia Directorate of Education. The experimental group was instructed on how to generate ideas, structure, draft, and edit their written pieces following Hamp-Lyons and Condon's (2000) model while the control group was instructed conventionally as prescribed in the Teacher's Book. The findings revealed that the portfolio group outperformed the conventionally-instructed group (at α≤ 0.05) in their overall writing performance and in their performance on the writing sub-skills of focus, development, organization, conventions and word choice.Key words: EFL, Jordan, portfolio assessment, writing performance Résumé Cette étude examine l'effet de l'évaluation par le portfolio sur les performances de l'écrit en général des apprenantes jordaniennes en dixième classe de la langue anglaise comme langue étrangere (EFL) ainsi que leurs performances des cinq sous-compétences de concentration, développement, organisation, conventions et choix des mots. L'étude est quasi-expérimentale dans laquel on compare un groupe expérimental avec un groupe contrôle de 20 élèves qui ont été délibérément selectionnées parmis les étudiantes de la dixème classe dans l'école publique des filles de la Direction Badia Nord-Est de l'éducation. La façon comment générer des idées a été enseigné au groupe expérimental ainsi que la structure, la redaction preliminaire, la revision et l'édition de leurs propres textes en suivant Hamp-Lyons et Condon (2000), tandis que le groupe côntrole a été enseigné d'une façon traditionelle exactement comme prescrit dans le livre de l'enseignant. Les résultats ont démontré que le groupe du portfolio a surperformé le groupe instruit traditionellement (à ≤ 0,05) dans leurs performances générales à l'écrit et celles des sous-compétences de concentration, développement, organisation, conventions et choix des mots.

The present study examines the potential effect of scaffolding instruction on Jordanian EFL tenth-grade students' overall writing performance and their performance on the sub-skills of focus, development, organization, conventions and word choice. The study follows a quasi-experimental experimental/control group, pre-/post test design. In the experimental group, 20 female tenth-grade students from the North-Eastern Badia Directorate of Education (Jordan) were taught to generate ideas, structure, draft, and edit their essays using agency scaffolding and the scaffolding principles of contextual support, continuity, intersubjectivity, flow, contingency and handover, within the Zone of Proximal Development. Another group of 28 students was instructed conventionally per the guidelines outlined in the Teacher's Book. After the treatment, descriptive statistics and ANCOVA were used to analyze the students' scores on the pre-test and the post test. The results showed that the scaffolding instruction group outperformed the control group (at α≤ 0.05) in their overall writing performance and in their performance on all writing sub-skills except the sub-skill of development.Does Scaffolding-Based Instruction Improve Writing Performance? 107

<p>This study examines the potential effect of scaffolding-based instruction and portfolio-based assessment on Jordanian EFL tenth grade students’ overall writing performance and their performance on the sub-skills of focus, development, organization, conventions and word choice. The study uses a quasi-experimental experimental/control group, pre-/posttest design. In the experimental group, 15 female tenth grade students from the North-Eastern Badia Directorate of Education (Jordan) were taught to generate ideas, structure, draft, and edit their written pieces using agency scaffolding, the scaffolding principles of contextual support, continuity, intersubjectivity, flow, contingency and handover, and a slightly adapted version of Hamp-Lyons and Condon’s (2000) Portfolio Model of collection, selection and reflection. A control group of 28 students were instructed conventionally per the guidelines of the teacher’s book. Using descriptive statistics and ANCOVA to analyze the students’ scores on the pre- and the posttests, the results showed that the group taught through scaffolding-based instruction and portfolio-based assessment outperformed the control group (at a≤ 0.05) in their overall writing performance and in their performance on the five writing sub-skills.</p>