  # Metric vs. Index: What's the Difference? ## Metric and Index Definitions

#### Metric

Of or relating to the metric system of measurement.

#### Index

An alphabetized list of names, places, and subjects treated in a printed work, giving the page or pages on which each item is mentioned.

#### Metric

(music) Of or relating to the meter of a piece of music.

A thumb index.

#### Metric

Of or relating to distance.

#### Index

A table, file, or catalog.

#### Metric

A measure for something; a means of deriving a quantitative measurement or approximation for otherwise qualitative phenomena (especially used in engineering).
What metric should be used for performance evaluation?
It's the most important single metric that quantifies the predictive performance.
How to measure marketing? Use these key metrics for measuring marketing effectiveness.
There is a lack of standard metrics.

#### Index

(Computers) A list of keywords associated with a record or document, used especially as an aid in searching for information.

#### Metric

(mathematics) A function for the measurement of the "distance" between two points in some metric space: it is a real-valued function d(x,y) between points x and y satisfying the following properties: (1) "non-negativity": $d\left(x,y\right) \ge 0$, (2) "identity of indiscernibles": $d\left(x,y\right) = 0 \mbox\left\{ iff \right\} x=y$, (3) "symmetry": $d\left(x,y\right) = d\left(y,x\right)$, and (4) "triangle inequality": $d\left(x,y\right) \le d\left(x,z\right) + d\left(z,y\right)$.

#### Index

Something that reveals or indicates; a sign
"Her face ... was a fair index to her disposition" (Samuel Butler).

#### Metric

(mathematics) A metric tensor.

#### Index

A character (☞) used in printing to call attention to a particular paragraph or section. Also called hand.

#### Metric

Abbreviation of metric system

#### Index

An indicator or pointer, as on a scientific instrument.

#### Metric

To measure or analyse statistical data concerning the quality or effectiveness of a process.
We need to metric the status of software documentation.
We need to metric the verification of requirements.
We need to metric the system failures.
The project manager is metricking the closure of the action items.
Customer satisfaction was metricked by the marketing department.

#### Index

(Mathematics) A number or symbol, often written as a subscript or superscript to a mathematical expression, that indicates an operation to be performed, an ordering relation, or a use of the associated expression.

#### Metric

Relating to measurement; involving, or proceeding by, measurement.

#### Index

A number derived from a formula, used to characterize a set of data.

#### Metric

Of or pertaining to the meter as a standard of measurement; of or pertaining to the decimal system of measurement of which a meter is the unit; as, the metric system; a metric measurement.

#### Index

A statistical value that represents the price or value of an aggregate of goods, services, wages, or other measurable quantities in comparison with a reference number for a previous period of time.

#### Metric

A function of a topological space that gives, for any two points in the space, a value equal to the distance between them

#### Index

A number that represents the change in price or value of stocks or other securities in a particular market, sector, or asset class.

#### Metric

A decimal unit of measurement of the metric system (based on meters and kilograms and seconds);
Convert all the measurements to metric units
It is easier to work in metric

#### Index

The stocks or other securities represented by an index.

#### Metric

A system of related measures that facilitates the quantification of some particular characteristic

#### Index

Index Roman Catholic Church A list formerly published by Church authority, restricting or forbidding the reading of certain books.

#### Metric

Based on the meter as a standard of measurement;
The metric system
Metrical equivalents

#### Index

To furnish with an index
Index a book.

#### Metric

The rhythmic arrangement of syllables

#### Index

To enter in an index.

#### Index

To indicate or signal.

#### Index

An alphabetical listing of items and their location.
The index of a book lists words or expressions and the pages of the book upon which they are to be found.

#### Index

The index finger; the forefinger.

#### Index

A movable finger on a gauge, scale, etc.

#### Index

(typography) A symbol resembling a pointing hand, used to direct particular attention to a note or paragraph.

#### Index

That which points out; that which shows, indicates, manifests, or discloses.

#### Index

A sign; an indication; a token.

#### Index

(linguistics) A type of noun where the meaning of the form changes with respect to the context; e.g., 'Today's newspaper' is an indexical form since its referent will differ depending on the context. See also icon and symbol.

#### Index

(economics) A single number calculated from an array of prices or of quantities.

#### Index

(science) A number representing a property or ratio; a coefficient.

#### Index

(mathematics) A raised suffix indicating a power.

#### Index

An integer or other key indicating the location of data, e.g. within an array, vector, database table, associative array, or hash table.

#### Index

A data structure that improves the performance of operations on a table.

#### Index

(obsolete) A prologue indicating what follows.

#### Index

(transitive) To arrange an index for something, especially a long text.
MySQL does not index short words and common words.

#### Index

To inventory; to take stock.

#### Index

To normalise in order to account for inflation; to correct for inflation by linking to a price index in order to maintain real levels.

#### Index

To measure by an associated value.

#### Index

To be indexical for (some situation or state of affairs); to indicate.

#### Index

(computing) To access a value in a data container by an index.

#### Index

That which points out; that which shows, indicates, manifests, or discloses; as, the increasing unemployment rate is an index of how much the economy has slowed.
Tastes are the indexes of the different qualities of plants.

#### Index

That which guides, points out, informs, or directs; a pointer or a hand that directs to anything, as the hand of a watch, a movable finger or other form of pointer on a gauge, scale, or other graduated instrument.

#### Index

A table for facilitating reference to topics, names, and the like, in a book, usually giving the page on which a particular word or topic may be found; - usually alphabetical in arrangement, and printed at the end of the volume. Typically found only in non-fiction books.

#### Index

A prologue indicating what follows.

#### Index

The second finger, that next to the pollex (thumb), in the manus, or hand; the forefinger; index finger.

#### Index

The figure or letter which shows the power or root of a quantity; the exponent.

#### Index

The ratio, or formula expressing the ratio, of one dimension of a thing to another dimension; as, the vertical index of the cranium.

#### Index

A number providing a measure of some quantity derived by a formula, usually a form of averaging, from multiple quantities; - used mostly in economics; as, the index of leading indicators; the index of industrial production; the consumer price index. See, for example, the consumer price index.

#### Index

A file containing a table with the addresses of data items, arranged for rapid and convenient search for the addresses.

#### Index

A number which serves as a label for a data item and also represents the address of a data item within a table or array.

#### Index

The Index prohibitorius, a catalogue of books which are forbidden by the church to be read; also called Index of forbidden books and Index Librorum Prohibitorum.

#### Index

To provide with an index or table of references; to put into an index; as, to index a book, or its contents.

#### Index

To adjust (wages, prices, taxes, etc.) automatically so as to compensate for changes in prices, usually as measured by the consumer price index or other economic measure. Its purpose is usually to copensate for inflation.

#### Index

To insert (a word, name, file folder, etc.) into an index or into an indexed arrangement; as, to index a contract under its date of signing.

#### Index

A numerical scale used to compare variables with one another or with some reference number

#### Index

A number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time

#### Index

A mathematical notation indicating the number of times a quantity is multiplied by itself

#### Index

An alphabetical listing of names and topics along with page numbers where they are discussed

#### Index

The finger next to the thumb

List in an index

#### Index

Provide with an index;
Index the book