The term "weight" has multiple related meanings in both scientific and everyday usage. Even among experts and in textbooks, weight is ambiguously defined as either the gravitational force on an object or operationally as the magnitude of the force an object exerts on a measuring scale. This poses both conceptual and language difficulties for learners, especially for accelerating objects where the scale reading is different from the gravitational force. But while the underlying physical constructs behind the two referents for the term weight (and their relation to each other) are well understood scientifically, it is unclear how the concept of weight should be introduced to students and how the language ambiguities should be dealt with. We investigated treatments of weight in a sample of twenty introductory college physics textbooks, analyzing and coding their content based on the definition adopted, how the distinct constructs were dealt with in various situations, terminologies used, and whether and how language issues were handled. Results indicate that language-related issues, such as different, inconsistent, or ambiguous uses of the terms weight, "apparent weight," and "weightlessness," were prevalent both across and within textbooks. The physics of the related constructs was not always clearly presented, particularly for accelerating bodies such as astronauts in spaceships, and the language issue was rarely addressed. Our analysis of both literature and textbooks leads us to an instructional position which focuses on the physics constructs before introducing the term weight, and which explicitly discusses the associated language issues.

Terminological and conceptual issues surrounding the definition of scientific terms have bothered teachers and students for many years. Some terms such as energy are not even usually defined, although they appear in different contexts of scientific communication, and others such as weight have debatable definitions, and for this reason the term weight is a great example to demonstrate general issues regarding terms and concepts. The term weight is defined in different ways, e.g., as the gravitational force or operationally as the force exerted by the body on its support. In an inertial situation, the magnitude of the gravitational force is equal to that of the support force. However, the two meanings are distinct when the object is in an accelerating situation (e.g., an accelerating elevator or on the surface of a rotating planet). Apart from these dichotomous definitions of weight, there are further language problems associated with each gravitational and operational definition of weight. This paper demonstrates these issues and asserts that arguing for which definition of weight is correct is not a viable approach to solve the language issue. The paper proposes an alternative route to deal with language issues facing weight and other related terms.

A quasi-experimental control group pre- and post-test study was used to determine the effect of a Multi-Step Inquiry (MSI) approach on pre-service elementary school teacher’s conceptual understanding. The MSI study involved the development of a conceptual workbook, and a Physical Science Concept Inventory. The conceptual workbook has activities that explicitly target students’ misconceptions in physical science. The inventory has three categories: forces and motion, heat and temperature, and electricity. Descriptive and inferential statistics were used to interpret the data. Independent t-tests were used to compare the experimental and comparison groups. Further, Cohen’s d and Hake’s g effect sizes were used to determine the effectiveness of MSI. Results indicated that the MSI approach as an effective teaching strategy for conceptual understanding. As such, the authors have made recommendations for both research and teaching.

In this study, conceptual and algebra-based physics students were engaged in scientific inquiry using Physics Education Technology (PhET) interactive simulations via semester-long group projects. The instructor and students used the Scientific Abilities Assessment Rubrics (SAAR) to evaluate project presentations and papers (formative assessment). The overall research project was evaluated using Lab Skills Self-Assessment (LSSA) survey (pre and post) and the post reflection survey. The Science Process Skills Inventory (SPSI) was used to analyze some of the students’ responses to the reflection survey. Quantitative analysis of the LSSA survey showed a large effect size for both conceptual and algebra-based physics students (Cohen’s d 0.8, in both courses). Qualitative analysis of the reflection surveys supported this apparent huge gain in lab skills and revealed considerable positive students’ experiences of the PhET simulations (88% of students indicated positive satisfaction).