طراحی و تبیین یک الگوی آموزشی چندرسانه‌ای مبتنی بر دانش تربیتی محتوا (PCK) برای آموزش مفهوم تغییر پارادایم در فیزیک: مطالعه موردی گذار از زمین مسطح به زمین کروی

Understanding the nature of science and the mechanisms through which scientific knowledge evolves constitutes a fundamental objective of contemporary science education. Among the key epistemological concepts that support this objective, the notion of paradigm shift occupies a central position because it enables learners to recognize science as a dynamic and evolving enterprise rather than a static collection of established facts. Despite its educational significance, teaching paradigm shifts remains challenging, particularly in physics education, where students often struggle to comprehend the historical, philosophical, and conceptual dimensions of scientific change. Traditional instructional approaches frequently fail to represent the complexity of scientific revolutions and the gradual processes through which scientific communities abandon established frameworks and adopt new explanatory models.

The present study aimed to design and explain a multimedia instructional model grounded in Pedagogical Content Knowledge (PCK) for teaching the concept of paradigm shift in physics education. The instructional design was developed around a historical case study examining the transition from the flat-Earth worldview to the spherical-Earth model. This historical transformation was selected because it provides a clear and accessible example of how scientific knowledge changes through the accumulation of evidence, the emergence of anomalies, conceptual crises, and the eventual acceptance of new paradigms.

Methodologically, the study employed a descriptive–analytical approach with an instructional design orientation. Relevant literature concerning Pedagogical Content Knowledge, history and philosophy of science, Kuhn’s theory of scientific revolutions, and multimedia learning was systematically reviewed to establish the theoretical foundations of the proposed model. Based on these foundations, a multimedia instructional unit was developed that integrated historical narratives, scientific evidence, visual representations, infographics, animations, educational videos, inquiry-based activities, and collaborative learning tasks. Particular attention was given to common student misconceptions regarding the shape of the Earth and the nature of scientific knowledge, as well as to pedagogical strategies capable of supporting conceptual change and meaningful learning.

The resulting instructional model provides a coherent framework for representing the stages of paradigm change through historically authentic examples and evidence-based reasoning. Historical accounts of observations made by Aristotle, the measurement of Earth’s circumference by Eratosthenes, and the gradual acceptance of the spherical-Earth model were incorporated to illustrate the dynamic nature of scientific progress. Furthermore, an inquiry-oriented activity was designed to allow students to reconstruct Eratosthenes’ experiment and engage directly with the empirical foundations underlying scientific claims. The integration of multimedia resources with historical and philosophical perspectives enhanced the accessibility of abstract concepts and facilitated deeper conceptual understanding.

The findings suggest that combining PCK-informed instructional design with multimedia learning principles and history-of-science approaches can provide an effective pathway for teaching complex epistemological concepts in physics education. The proposed model promotes student engagement, supports evidence-based reasoning, strengthens scientific literacy, and encourages learners to view scientific knowledge as tentative, revisable, and historically situated. In addition, the model offers practical guidance for physics teachers seeking to enhance their Pedagogical Content Knowledge when teaching abstract concepts related to the nature of science. Beyond the specific case examined in this study, the instructional framework may be adapted to other scientific concepts involving historical transformations and conceptual change, thereby contributing to more meaningful and authentic science learning experiences.