Conceptual Development And Conceptual Change:
Examining The Influence Of Formative Assessment On Student Achievement
This study explored the effect of formative assessment on student achievement in science. Research in science education has shown that students enter science classrooms with previously formed explanatory models of the natural world; these naive "mental models" have a substantial influence on their learning of scientific conceptions (e.g. Vosniadou & Brewer, 1992). In general, conceptual change describes the pathway from pre-instructional or prior conceptions to a post-instructional or desired conception (e.g. Duit, 1999; Posner, Strike, Hewson, & Gertzog; 1982). Research has shown that conceptual change is difficult to promote; for example, students may accumulate multiple conceptions over the course of instruction, including both new misconceptions and more scientifically-sound conceptions. Helldén and Solomon (2004) found that although students tended to evoke the same, less-scientific conceptions over time, they could produce more scientifically-sound conceptions during interviews with appropriate prompting. Such accumulation of conceptions might be considered conceptual development rather than conceptual change. Students can recall scientifically-sound conceptions they have learned and may use them to reason, but they do so in partnership or hybridization with their less-scientific prior conceptions (Vosniadou & Brewer, 1992).
Student achievement in science may be conceptualized as composed of four different but overlapping types of knowledge -- declarative (knowing that), procedural (knowing how to), schematic (knowing why), and strategic (knowing how knowledge, applies to particular situation and monitoring progress). These four types of knowledge are distinguishable in theory, and may be assessed by different types of measures (Li, 2001; Ayala, Shavelson, Yin, & Schultz, 2002; Shavelson et al., 2008). As such, it is important to identify achievement goals according to different types of knowledge students are expected to gain and to focus instruction and assessment properly. In this case, conceptual change focuses on developing increasingly more scientifically-sound schematic knowledge, whereas gains in declarative or procedural knowledge may be more closely related to conceptual development.
Formative assessment, which focuses on providing immediate feedback by acting upon student understanding during the course of instruction, and conceptual change have both have been linked to increased student achievement (e.g. Black & William, 1998; Wang, Haertel & Walberg, 1993). Formative assessment is an instructional strategy that helps teachers to assess students' current understanding, identify the gap between current understanding and expected understanding, and provide immediate and useful feedback to students on how to close the gap. Formative assessment ranges from formal (e.g. embedded, planned-for interactions between teacher and entire class) to informal (e.g. on-the-fly interactions between teacher and class or student).
In this study, the links between formative assessment and conceptual development and conceptual change were explored. Specifically, this study asked: (1) Does formative assessment promote conceptual development, and (2) Does formative assessment promote conceptual change? It was hypothesized that conceptual change-focused formative assessment would foster conceptual change, in addition to supporting conceptual development. It was further hypothesized that all students will show gains in conceptual development as indicated by measures of declarative and procedural knowledge, but that students exposed to conceptual change-focused formative assessment would also show gains in conceptual change as indicated by measures of schematic knowledge or mental models.
To research the effect of formative assessment on conceptual development and conceptual change, a small randomized experiment was conducted. In Phase I of the study, 52 6th graders were randomly assigned to a treatment or control group; in Phase II of this study, 50 7th graders were randomly assigned to a treatment or control group. Both the control and experimental groups were taught about sinking and floating by the same teacher (the author) with identical curriculum materials and activities. In addition, the experimental group received three sets of embedded formative assessments focused on conceptual change around the topic of why things sink and float during the course of instruction.
In Phase I of this study, both groups were kept at the same pace through the entire sequence of investigations. The control condition spent more time on some of the more critical FAST lessons, gathering additional data to support the theories the curriculum expected they would develop at a particular juncture but not receiving structured experiences aimed at addressing misconceptions. In Phase II, students in the control condition spent roughly the same time on each FAST lesson as those in the experimental condition (e.g. they finished the sequence of activities earlier because they did not have class sessions devoted to the RLs inserted at critical junctures) but participated in the formal assessments as a block of activities after they finished the FAST investigations and posttest measures. In other words, in addition to replicating Phase I, Phase II included a Reflective Lesson section for the control group after the end of the experiment proper, followed by a post-posttest.
Overall, it was found that embedding conceptual change-focused formative assessments in the FAST curriculum significantly influenced conceptual change. It was also found that all students experienced significant gains in terms of their conceptual development, regardless of exposure to the formative assessments.
This study connected two previously isolated but theoretically linked educational frameworks: conceptual change and formative assessment. It was found that formative assessments can be used to promote conceptual change. It was also found that conceptual change is different than conceptual development - students who show gains on measures of declarative and procedural knowledge do not necessarily show gains on measures of schematic knowledge. This implies that if a goal of science instruction is to support student development of scientifically-sound conceptions, then conceptual change must be specifically targeted via instructional strategies such as embedded formative assessment.