Critical literacy practices have moved their interest from Freirean binary analyses (e.g. oppressor versus oppressed) to more complex perspectives, where in a text the author/speaker is (dis) aligned with different discourse communities. Despite the fact that these teaching practices that are based in multiple discources are gaining attention, little work has been done on the assessment of the teaching practices. During the last decades, the literacy activities researches have focused on the teacher-student interactions and the teacher talks (asking questions, types of questions), neglecting the final text production, which is also a significant factor in the evaluation of literacy practices. In this paper, after the implementation of polyphonic literacy practices in a rural junior high school in Crete, Greece, the teacher-researcher assessed the final student written products using the Appraisal Theory. Further qualitative methodological data gathering sources enhanced the identification of the contextual factors that can explain in depth the discourses the students (re)produced in their texts. These findings suggest that Appraisal Theory combined with such methodological choices, where the context is identified, is more supportive in the evaluation of these complex critical literacy practices and provides the teacher and students fruitful feedback concerning critical literacy awareness.