# quantity

Quantity ( Latin quantitas "size", "amount") denotes the amount or number of substances or objects or the frequency of events . Quantity is expressed in numerical values or the specification of dimensions . In science, determining the quantity is called quantification .

## Examples

In planning and forecasting , quantitative approaches describe forecasting methods that try to use mathematical algorithms to forecast future events (such as a requirement ).

In portfolio management and in the area of investment funds , quantitative management describes the composition of a fund or portfolio using mathematical approaches.

## Quantity and quality

In many areas, such as production technology , qualitative requirements conflict with quantitative ones. This led to the expression “ quantity is not the same as quality” .

For example, a production facility that can produce 1000 screws in a certain period of time could also produce 2000 screws in the same period if it is run faster ( intensity adjustment ). However, this would mean that the machines would no longer run optimally and the screws produced would be of poor quality ( faulty production ). If the manufacturing tolerances were outside the norm as a result, the company could produce twice as many screws (quantity), but not sell them because of the lack of quality .

When it comes to purchasing, the phrase `` quantity is not the same as quality '' also applies : if a retailer buys a pallet of half-spoiled fruit for a low price at the wholesale market, the quantity is high, but the quality is low. In contrast, unspoiled fruit would be more expensive, but of high quality.

However , using the term quantity as the opposite of quality is factually incorrect. The quantity as an indication of the numerical value of a metric quantity always contains qualitative aspects (relating to the properties of a thing). An example from medicine: the blood pressure is 120/80 mmHg. The quantitative determination relates to the quality of blood pressure , which is given in the unit of measurement mmHg; this determination can also include the qualitative aspect that the blood pressure is within the normal range . All quantitative information relates to certain qualities that are quantitatively recorded by the quantitative information. This applies in particular to medical findings , which are always composed of qualitative and quantitative statements. The well-known quote from Paracelsus from 1538 shows how closely quality and quantity are linked : All things 'are poison and nothing without' poison; the dose alone makes a thing 'not a poison ; (see also poison , dose , lethal dose ).

The Nobel Prize winner for Physics Philip Warren Anderson has about 1972 an article in Science written ( English More is Different ).