Quinacridone red and violet are visually different colors, an observation confirmed by their visible reflectance spectra and CIE L*a*b* coordinates. However, their IR spectra are extremely similar. Though chemically identical, the two quinacridones are polymorphs. In this experiment, designed for and tested by nonscience majors, the pigments are…

It may be asserted that there is no more effective deterrent to crime than the certainty of detection. Equally true is that there is no surer way to establishing identity than by fingerprints. The detection of fingerprints at the scene of crime is therefore one of the most powerful tools available in casework investigations. However, if the crime…

Mass spectrometry is frequently introduced to undergraduate students as an instrument for both qualitative and quantitative chemical analysis. One of the most common uses of mass spectrometry (MS) is to deduce or confirm a compound's chemical formula, by relying on high-resolution accurate-mass measurements. However, like all forms of instrumental…

This paper describes a student-centered approach to teaching and learning physics in a high school classroom. The teacher designs and uses a 5E learning cycle to teach series and parallel electric circuits. This article provides an example of the implementation of 5E model for a physics lesson to address three-dimensional learning-science and…

Evidence-based reasoning and critical thinking are two crucial scientific abilities of students, sharing a close relationship with each other critical thinking is not just randomly refuting but a logical-reasoning thinking based on solid evidence. However, in real teaching circumstances of experiment classes, students easily directly accept the…

The ability to "engage in argument from evidence" is one of the eight practices identified in the "Next Generation Science Standards" as well as an emerging focus of undergraduate chemistry curricula. Guiding students to make evidence-based claims that engender argumentation will require faculty to revise conventional…

This paper uses evidence-centered assessment design (ECD) to structure and analyze a laboratory activity where students collect and represent titration curve data to determine acid strength in terms of molarity and dissociation constant. Following principles of multidimensional learning, the activity prompts students to demonstrate knowledge of…

This study explores one teacher's instructional method for teaching life sciences using argumentation and argumentative writing rather than simple templates for writing claims and evidence. The microethnographic discourse analytic case study reported here included the teacher and 26 "advanced" eighth-grade students in a suburban middle…

As well-developed as they may be, standards are not curriculum. It is the job of teachers and curriculum teams to use the Standards as the basis for designing the specific pathway for teaching and learning. In this article, the authors explore the use of Understanding by Design (UbD), a widely-used curriculum development framework, for honoring…

Avogadro's conception of the structure of gases was not widely accepted by his contemporaries--probably because the hypothesis was not supported by direct evidence. This problem is rarely addressed in schools. This article discusses the difficulties that accompany the acceptance of new ideas. Such difficulties may be associated with the ways in…

A medium-scale quantitative study (n = 90) found that 10-11-year-old pupils dealt with theory and evidence in notably different ways, depending on how the same science practical task was delivered. Under the auspices of a 2×2 part-randomised and part-quasi experimental design, pupils were asked to complete a brief, apparently simple task involving…

This research study is an investigation of student-laboratory (i.e., lab) learning based on students' perceptions of experiences using questionnaire data and evidence of their science-laboratory performance based on paper-and-pencil assessments using Maryland-mandated criteria, Montgomery County Public Schools (MCPS) criteria, and published…

Laboratory experience and skills are not only essential for success in science studies, but are the most exciting and rewarding aspects of science for students. As a result, many biology teachers have become critical of the efficacy of cookbook-type laboratory activities as well as the purposes, practices, and learning outcomes of lab experiments…

The use of an internal standard is a conventional and convenient way to monitor the conversion of one or several monomers during a controlled radical polymerization. However, the validity of this technique relies on an accurate determination of the initial monomer-to-internal standard ratio, A[subscript 0], because all subsequent calculations of…

Evaluating the strength of evidence in noisy data is a critical step in scientific thinking that typically relies on statistics. Students without statistical training will benefit from heuristic models that highlight the logic of statistical analysis. The likelihood associated with various coin-tossing outcomes gives students such a model. There…