Teaching Measurement in the Introductory Physics Laboratory

Abstract

Traditionally physics laboratory courses at the freshman level have aimed to demonstrate various principles of physics introduced in lectures. Experiments tend to be quantitative in nature with experimental and data analysis techniques interwoven as distinct strands of the laboratory course.1 It is often assumed that, in this way, students will end up with an understanding of the nature of measurement and experimentation. Recent research studies have, however, questioned this assumption.2,3 They have pointed to the fact that freshmen who have completed physics laboratory courses are often able to demonstrate mastery of the mechanistic techniques (e.g., calculating means and standard deviations, fitting straight lines, etc.) but lack an appreciation of the nature of scientific evidence, in particular the central role of uncertainty in experimental measurement. We believe that the probabilistic approach to data analysis, as advocated by the International Organization for Standardization (ISO), will result in a more coherent framework for teaching measurement and measurement uncertainty in the introductory physics laboratory course.

Epistemology and expectations survey about experimental physics: Development and initial results

“…Some laboratories have introduced new educational technologies (e.g., microcomputer-based labs [7] and VPython [8,9]), others have added an emphasis on particular scientific practices (e.g., measurement and uncertainty [10,11], developing testable questions and designing experiments [12,13], and scientific argumentation [14]), while others have pushed the lab course closer to cuttingedge research by introducing modern physics concepts and apparatus (e.g., single photon quantum optics experiments [15,16]), and others have demonstrated improved conceptual learning gains through research-based lab activities [17]. The diversity of responses reflects both the diversity of goals for the laboratory and the flexibility and adaptability of the laboratory environment to meet many different goals.…”

Race to improve student understanding of uncertainty: Using LEGO race cars in the physics lab

“…Experimentation and measurement lie at the heart of physics, and it is important that students develop an understanding of these concepts. 14 However, the goal of measurement is often seen by these students almost exclusively acquiring a single "point" value for the quantity they are investigating, 15 and not also realizing that there is measurement error and other aspects of variability which creates uncertainty in the point estimate. Lying at the heart of the problem is the great difficulty students have in translating the "words" of a problem into a "picture" of reality, where physical objects relate to each other through physical laws.…”

“…14,17 Yet conducting proper analysis of experimental uncertainty is a primary goal of introductory physics labs. 13 Previous studies 18,19 found that students leave introductory physics laboratory courses with an ability to carry out certain procedures, but lack a coherent understanding for the nature of uncertainty, irrespective of the student profile, or the way in which the laboratory course was delivered.…”

“…Creating experiences that require students to build a conceptual understanding of measurement, perhaps before their ability to undertake the calculations, can be a solution. 14 Thus, it is important to facilitate an introductory lab that enables students to understand uncertainty through interactive learning, to build lab skills through scientific investigation, and to engender positive attitudes toward physics. 22 Consistent with the AAPT recommendation that an early positive experience can set up a student for a productive longer-term relationship with physics, we set out to design an engaging, interactive, and fun first year introductory physics lab that introduced students to pivotal concepts in a realworld way.…”

Doing Science or Doing a Lab? Engaging Students with Scientific Reasoning during Physics Lab Experiments

“…Halfway through the second semester of the course, students worked in pairs or groups of three to determine the index of refraction (n) of a plexiglass prism through the application of Snell's Law, the critical angle for Total Internal Reflection, and Brewster's Angle. The students had received instruction earlier in the year on assessing whether measurements were in agreement and on quantifying uncertainties from digital and analog scales and due to statistical fluctuations [7].…”