What Are Measures?

The division of a piece of music into measures helps musicians maintain a consistent rhythm. Philosophers have explored the many metaphysical, semantic and epistemological issues surrounding measurement. Operationalists and conventionists conceive of measurement as the mapping of qualitative empirical relations to relations among numbers. Realists, however, disagree with this model-based account of the nature of measurable quantities.


Length is a dimension that determines the distance between two points. It is one of the three dimensions that are needed to describe an object’s shape, along with width and height.

The length of an object can be measured using a ruler or tape measure. It can also be expressed as a ratio of its side to its width or height. Usually, when describing the dimensions of an object, length is listed first followed by width and then height. This is called dimensional analysis.

There are many different units that can be used to measure length, including the metric system and the customary United States units of inches, feet and yards. The SI unit of length is the meter, which was defined by scientists from multiple countries. Non-standard units of length may be based on the size of the human body or other factors. A meter is just one of many possible units that could be used to measure length, but it is agreed upon by scientists and is widely accepted around the world as a standard measurement of length.


Weight is the force exerted on a body by gravity, calculated as an object’s mass multiplied by its acceleration due to gravity. Although the words “weight” and “mass” are often used interchangeably outside of science, they mean very different things: mass is a measurement of how much matter something has, while weight is a measure of gravitational force.

In routine clinical settings, body weight measurements are frequently documented in electronic health record (EHR) systems and can be utilized for a variety of purposes including monitoring patient outcomes and program evaluation. However, a significant amount of variability exists in the methodologies that are used to construct these measures.

The EHR data-driven literature has been hampered by a lack of reporting on key attributes used to construct these measures. Identifying and promoting consistency in these approaches can facilitate the development of a stronger research foundation. In particular, improving methods for constructing these outcome measures will support robust evidence building, transparency in reporting, and replicable science.


Capacity is an essential enabling factor for all entities, from global organizations to local communities, working in complex environments. The concept of capacity has emerged as a key consideration in international development work, particularly among the poorest countries.

The ability to learn from experiences and adapt is a central theme of capacity development, which requires ongoing assessment and feedback to ensure learning and improvement. To do so, project staff should design assessment tools that are themselves a part of the capacity-building process.

A number of different measures of physical capacity have been used in the literature, ranging from fully observational to judgement-based. IRT is an attractive approach because it allows for the inclusion of both self-report and performance measures while also delivering improved measurement precision. The results show that IRT is able to differentiate between persons with varying levels of physical capacity. However, the results suggest that self-report items are more effective at discriminating individuals at low levels of physical capacity, while performance-based items are better at identifying differences at higher levels of physical capacity.


Measurements are used in science and many everyday activities. They are defined on a scientific basis and overseen by governmental or independent agencies, such as the General Conference on Weights and Measures, which governs the international system of units.

Time is an abstract measurement of elemental changes over a non-spatial continuum, denoted by numbers or by named periods such as seconds, hours, days, weeks, months and years. It appears to be an irreversible sequence of events and a relative measure between two points on the continuum.

Some philosophers, such as Aristotle, have argued that time exists only in relation to change. Others, such as Leibniz, have argued that while change can be faster or slower, time itself is not change. Instead, they suggest that time is the overall order of events that are detectable. This is called the relational theory of time. If this theory is correct, then the question of whether or not time exists must depend on what else is known about the universe in which we live.