Indicator may refer to:

Biology

Environmental indicator Environmental indicators are simple measures that tell us what is happening in the environment. Since the environment is very complex, indicators provide a more practical and economical way to track the state of the environment than if we attempted ...

of environmental health (pressures, conditions and responses) *

Ecological indicator Ecological indicators are used to communicate information about ecosystems and the impact human activity has on ecosystems to groups such as the public or government policy makers. Ecosystems are complex and ecological indicators can help describe ...

of ecosystem health (ecological processes) *

Health indicator Health indicators are quantifiable characteristics of a population which researchers use as supporting evidence for describing the health of a population. Typically, researchers will use a survey methodology to gather information about a populatio ...

, which is used to describe the health of a population *

Honeyguide Honeyguides (family Indicatoridae) are near passerine birds in the order Piciformes. They are also known as indicator birds, or honey birds, although the latter term is also used more narrowly to refer to species of the genus '' Prodotiscus''. Th ...

s, also known as "indicator birds", a family of Old World tropical birds ** ''Indicator'' (genus), a genus of birds in the honeyguide family *

Indicator species A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...

, a species that defines a characteristic of an environment *

Indicator bacteria Indicator bacteria are types of bacteria used to detect and estimate the level of fecal contamination of water. They are not dangerous to human health but are used to indicate the presence of a health risk. Each gram of human feces contains app ...

, bacteria used to detect and estimate the level of fecal contamination of water *

Indicator organism Indicator organisms are used as a proxy to monitor conditions in a particular environment, ecosystem, area, habitat, or consumer product. Certain bacteria, fungi and helminth eggs are being used for various purposes. Types Indicator bacteria ...

, organisms used to measure such things as potential fecal contamination of environmental samples *

Indicator plant A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...

, a plant that acts as a measure of environmental conditions *

Indicator value Indicator value is a term that has been used in the ecology of plants for two different indices. The older usage of the term refers to Ellenberg's indicator values from 1974, which are based on a simple ordinal classification of plants according t ...

, one of two terms in ecology referring to the classification of organisms *

Iodine–starch test The iodine–starch test is a chemical reaction that is used to test for the presence of starch or for iodine. The combination of starch and iodine is intensely blue-black. The interaction between starch and the triiodide anion () is the basis f ...

, a method to test for the presence of starch or iodine.

Chemistry

Complexometric indicator A complexometric indicator is an ionochromic dye that undergoes a definite color change in presence of specific metal ions. It forms a weak complex with the ions present in the solution, which has a significantly different color from the form ex ...

, a chemical detector for metal ions in complexometric titrations. *

Humidity indicator card A humidity indicator card (HIC) is a card on which a moisture-sensitive chemical is impregnated such that it will change color when the indicated relative humidity is exceeded. This has usually been a blotting paper impregnated with cobalt(II) ch ...

, a card impregnated with chemicals that change colour when a particular humidity is exceeded. *

pH indicator A pH indicator is a halochromic chemical compound added in small amounts to a solution so the pH (acidity or basicity) of the solution can be determined visually or spectroscopically by changes in absorption and/or emission properties. Hence, ...

, a chemical detector for protons in acid-base titrations. *

Redox indicator A redox indicator (also called an oxidation-reduction indicator) is an indicator which undergoes a definite color change at a specific electrode potential. The requirement for fast and reversible color change means that the oxidation-reduction e ...

, a chemical detector for redox titrations. *

Zeta potential Zeta potential is the electrical potential at the slipping plane. This plane is the interface which separates mobile fluid from fluid that remains attached to the surface. Zeta potential is a scientific term for electrokinetic potential in coll ...

, a property of interfaces in fluids for Zeta potential titration.

Economics

Economic indicator An economic indicator is a statistic about an economic activity. Economic indicators allow analysis of economic performance and predictions of future performance. One application of economic indicators is the study of business cycles. Economic i ...

Performance indicator A performance indicator or key performance indicator (KPI) is a type of performance measurement. KPIs evaluate the success of an organization or of a particular activity (such as projects, programs, products and other initiatives) in which it en ...

Technical indicator In technical analysis in finance, a technical indicator is a mathematical calculation based on historic price, volume, or (in the case of futures contracts) open interest information that aims to forecast financial market direction. Technical indi ...

, a tool used in the technical analysis of financial securities

Mathematics, engineering, and industry

Indicator (distance amplifying instrument) In various contexts of science, technology, and manufacturing (such as machining, fabricating, and additive manufacturing), an indicator is any of various instruments used to accurately measure small distances and angles, and amplify them to ma ...

, any of various instruments used to accurately measure small distances, and amplify them to make them more obvious *

Indicator (metadata) In metadata, an indicator is a Boolean value that may contain only the values true or false. The definition of an Indicator must include the meaning of a true value and should also include the meaning if the value is false. If a data element may ...

, a Boolean value that may contain only the values true or false and includes the meaning of these values *

Indicator (statistics) In statistics and research design, an indicator is an observed value of a variable, or in other words "a sign of a presence or absence of the concept being studied". Just like each color indicates in a traffic lights the change in the movement. Fo ...

, a concept in statistics, research design and social sciences *

Indicator diagram An indicator diagram is a chart used to measure the thermal, or cylinder, performance of reciprocating steam and internal combustion engines and compressors. An indicator chart records the pressure in the cylinder versus the volume swept by the ...

, a graph of pressure against stroke within a piston engine *

Indicator function In mathematics, an indicator function or a characteristic function of a subset of a set is a function that maps elements of the subset to one, and all other elements to zero. That is, if is a subset of some set , one has \mathbf_(x)=1 if x\i ...

of a subset of the domain, a concept in mathematics *

Indicator net Constructed using light steel nets, indicator nets were often anchored at various depths to the sea bed around Allied naval bases during both world wars. They were intended to entangle U-boat traffic of the enemy, even though the submarines often ...

, nets anchored at various depths to the sea bed around Allied naval bases during World War II intended to entangle U-boat traffic of the enemy *

Indicator of compromise Indicator of compromise (IoC) in computer forensics is an artifact observed on a network or in an operating system that, with high confidence, indicates a computer intrusion. Types of indication Typical IoCs are virus signatures and IP addresses ...

, an artifact observed in computer forensics that indicates an intrusion

Other uses

* ''Indicator'' (Deine Lakaien album), 2010 * ''Indicator'' (Onward to Olympas album), 2012 *

Indicator Island Indicator Island () is an island long, lying west of the northwest end of Galindez Island in the Argentine Islands, Wilhelm Archipelago, Antarctica. It was charted and named in 1935 by the British Graham Land Expedition under John Rymill. A win ...

, in the Argentine Islands of Antarctica * ''The Indicator'' (1819–1821), a weekly literary journal edited by

Leigh Hunt James Henry Leigh Hunt (19 October 178428 August 1859), best known as Leigh Hunt, was an English critic, essayist and poet. Hunt co-founded '' The Examiner'', a leading intellectual journal expounding radical principles. He was the centr ...

* ''The Indicator'', a daily podcast produced by

Planet Money ''Planet Money'' is an American podcast and blog produced by NPR. Using "creative and entertaining" dialogue and narrative, ''Planet Money'' claims to be "The Economy Explained." History The podcast was created by Alex Blumberg and Adam Davids ...

* A synonym for the

turn signal The lighting system of a motor vehicle consists of lighting and signalling devices mounted to or integrated into the front, rear, sides, and in some cases the top of a motor vehicle. They illuminate the road ahead for the driver and increase th ...

of an automobile {{disambiguation