The portfolio as an example of alternative assessment refers to the students' works that are collected over a specific period of time and shows the learning process as well as the students' strengths and weaknesses. So, this study was conducted to investigate the impact of portfolio assessment (PA) on the argumentative writing performance of upper intermediate EFL learners. For this purpose, the researchers selected two intact groups of upper intermediate learners, then put them randomly into two groups of experimental groups (N=24) and control group (N=24) whose homogeneity in language proficiency was checked by First Certificate in English test (FCE). The pre-test was given to both groups. Both groups received the same teaching materials for 10 sessions. The evaluation of the learners' writing in the experimental group was done by the portfolio system (portfolio-based evaluation) and in the control group by the more traditional evaluation system (non-portfolio-based evaluation). The findings of the MANCOVA test revealed that portfolio group outperformed the control group in writing performance and also the results indicated that portfolio was effective in improving the writing components including generic Features, textual language, syntactical language and spelling. The findings of the present study showed the importance of involving upper intermediate EFL learners both in the learning and assessing processes and offer pedagogical implications.
Abdollahzadeh et al. (Mon,) studied this question.