To get the most out of your metrics, prioritize what’s most important to stakeholders and refine them so that they’re feasible to track. Make sure your metrics are visible to the right people to foster a culture of accountability and ownership.
In mathematics, a measure is a function assigning to each set of a countable disjoint union a value such that it has sigma finiteness and countable additivity.
Types of Measures
Measures are used in Power BI to create dynamic, context-dependent calculations and add values to visualizations. They differ from Calculated Columns which are static values that cannot be altered or created within a report.
There are four types of measurement scales (nominal, ordinal, interval and ratio) that classify gathered data into distinct variables for different purposes. Each scale has its own properties and benefits.
All measurements are statistical in nature, and the process of measurement involves reducing uncertainty to arrive at an estimated value. Therefore, the final result is not necessarily an exact representation of the underlying property being measured.
In general, a measure is based on an agreed upon standard, such as the International System of Units (SI) – the seven fundamental units are kilogram, metre, candela, second, ampere, kelvin and mole. Other common measures include time, length, weight and temperature. All of these are derived from historically agreed upon standards, not any inherent physical properties or characteristics of the objects being measured.
Units of Measures
Like a graph without axis labels, a quantity without its corresponding unit of measure is meaningless. Units of measurement are defined and regulated for the sake of consistency, clarity, and precision in science and commerce. A single physical unit — the meter, for example — may be defined and used in many different ways.
Historically, units of measure were often based on the dimensions of human beings, such as the cubit based on arm length or the pace based on the distance of a stride. More recently, scientific societies have developed and agreed upon a universal system of units called the International System of Units or SI that contains seven base units (see Table 2.5.1).
The metric system, for example, relies on such units as the meter for length and the kilogram for mass. Conversions between these and other units of measures are made possible by decimal prefixes that add to or subtract from the base units.
Measurement Methods
Measurement techniques are the tools, devices and strategies that enable accurate and precise data collection. They are an essential part of engineering and allow for the assessment, monitoring and optimization of processes. These tools also ensure that all aspects of an engineering project are in line with set standards and safety precautions.
There are two kinds of measurement methods: direct and indirect. In direct measurement, the value of a quantity is measured directly in accordance with its definition. Examples include the use of scales, vernier callipers and micrometers. In indirect measurement, the value of a quantity is obtained by measuring other quantities that are functionally related to it. Examples include the use of dial gauges, gauge blocks and ring gauges.
In both methods, the measurements are subject to error. However, the errors can be minimized by using suitable measurement techniques and ensuring that the instrument used is working correctly. In addition, the results are compared with reference values that have been calibrated to produce known uncertainty levels.
Measurement Standards
A measurement standard is the physical embodiment of a unit of measure to which other measurement devices can be calibrated. It can be a physical object or a measuring instrument that can be used to define, realize, conserve, and reproduce units of measurement, such as the international prototype kilogram consisting of a platinum-iridium bar kept at the International Bureau of Weights and Measures in Sevres, France. A measurement standard can also be a reference material that is used to ensure traceability of a measurement.
NIST is responsible for maintaining national standards—realizations of the SI—for most basic measurement quantities and many derived measurement quantities. These include, for example, the seven fundamental metric system base units of length, mass and time; atomic clocks that serve as the foundation for civilian time in the United States; and a wide range of measurement tools that help scientists and industry develop advanced products. There are many other categories of measurement for which there are not yet standards, but for which there is a strong desire to have standards available.