There appears to be no published knowledge regarding how humans use unit conversions. Until very recently, acquiring such data would be essentially impossible, but mobile devices have now enabled many questions to be answered through passive "crowdsourcing" of big data sets. This work details the analysis of five years of anonymous user…

The measurement of the force acting between two parallel, current-carrying wires is known as Ampère's experiment. A mechanical balance was historically employed to measure that force. We report a simple experiment based on an electronic precision balance that is useful in clearly showing students the existence of this interaction and how to…

Presents the views of a high school physics teacher toward The International System of Units (SI). (HM)

Presents the author's perspective for accepting an approximation to The International System of Units (SI). Some alternatives to the SI form are also presented. (HM)

Discusses the relationship between the SI units and fundamental physical constants. (SL)

The mathematical nature of the catagories of base unit, supplementary unit, and derived unit in the SI system of measurement is explained. (SL)

Describes several developments in atomic clocks and frequency standards pointing out the feasibility and practicality in adopting a unified standard of time and frequency to replace other base standards of length, mass, and temperature. (GA)

A brief article stressing the need for care and accuracy in selecting materials to be used in teaching metrication. Caution should be taken in readability and interpretable rulings. (Author/EB)

Presents an introductory activity in the use of arbitrary measuring units, using simple materials found in school or at home. Materials are listed and activities provided. (EB)

Describes a method used to introduce the metric system to five year olds. Suggestions and necessary materials are included. (EB)

Presents a survey of the International System of Units, usually denoted by its French abbreviation, SI (Systeme International), how it came about, and how it is likely to develop in the future. Describes SI units (base, derived, and supplementary) and new definitions for base units. (Author/SK)

Describes development of units to teach measuring skills using manipulative materials. Concepts fostered include repetition of identical units, comparison, and standardized units. Descriptions of activities on length and area and mass are given, as well as references for additional activities. (JM)

Discusses the history and evolution of measurement standards from 3000 BC to the modern metric system. Traces measurement techniques from comparisons with the human body to use of atomic clocks and lasers to establish the length of a meter. (JM)