A Situated-Cognition Perspective of the Atomic/Molecular Model of Matter Learning Progression

• In Event: Tracing Learning Progressions/Trajectories: Novel Theoretical and Methodological Perspectives at the Intersection of Mathematics and Science

Abstract

The atomic/molecular model of matter is introduced in middle school in many curricula (NRC, 2012; Department of Basic Education, 2011). Several studies have used assessment instruments to describe a LP of the study of matter in western schooling systems (e.g., Hadenfeldt, et al., 2016; Johnson & Tymms, 2011), with some incorporating picture-based items (Johnson, 2013, Authors, 2013; Nyachwaya et al., 2011; Merritt & Krajcik, 2013). However, none of these studies applied the LP approach to compare students from different school systems and cultural backgrounds. Scientific language and visual symbols are situated in a cultural context (Goodings, 2004). Moreover, dual-coding theory (Clark & Paivio, 1991) stipulates that images and verbal content are processed in two parallel cognitive systems. Thus, from a situated cognition perspective (Collins & Greeno, 2011), using both visual and pictorial items in assessments allows to examine how cultural and curricular contexts shape LPs.
The current study was conducted in South Africa and in Israel. The South African sample were 8th to 10th grade students from a rural, low socio-economic school, and the Israeli sample were 7th grade students from middle-upper class schools. The Israeli students learned science in their mother tongue whereas the South-African students learned science in English but speak Siswati at home. In both locations we used two versions of the LP assessments with items adapted from prior studies. Half of the items were text-based and half picture-based – as shown in figures 4 & 5. We used random assignment to distribute each version of the assessment among students (i.e. half of each sample received one version of the items and the other half received the other version). Four identical items were included to link the two versions (Haebara, 1980).
We used dichotomous Rasch analysis to compare item difficulties and found significant differences between the Israeli and South African groups in almost all of the items. Some of the differences are related to the school context, and others are related to differences in language among groups. Nevertheless, the discrepancy between equivalent verbal and pictorial versions of items were similar in both samples. Pictorial versions of items concerning the configurations of particles (e.g., figure 4), were easier than the verbal ones and the verbal versions of items concerning particle motion (e.g., figure 5), were easier than the pictorial ones. The differences between the pictorial and verbal items were even more pronounced for choices representing lower levels of understanding. For example, answer C in figure 2, relates the expansion of a football to air particles that move from its center to the sides. 20/121 students from the Israeli sample chose this option in the pictorial version and only 6/112 in the verbal version.
Our study shows that student responses are very sensitive to the choice of words and pictorial details in assessment items, and that curricular and cultural contexts, play significant roles in LP assessment. We conclude that the level-based atomic/molecular model of matter LP is not universal and needs to be adjusted to meet curricular and cultural contexts.

Authors

• Elon Langbeheim, Ben-Gurion University of the Negev

• Sevil Akaygun, Bogazici University

• Emine Adadan, Bogazici University

• Manzini Hlatshwayo, University Of Johannesburg

• Umesh Ramnarain, University Of Johannesburg