(IEEE) (1) A qualitative assessment of correctness or freedom from error. (2) A quantitative measure of the magnitude of error. Contrast with precision. (CDRH) (3) The measure of an instrument's capability to approach a true or absolute value. It is a function of precision and bias. See: bias, precision, calibration.

The success in estimating the true value. The closeness of an estimate of a characteristic to the true value of the characteristic of the population.

The extent to which an experimental measure is free from error. go to glossary index

The ability of a measurement to match the actual value of the quantity being measured.

Represents how close the actual position of a nanopositioner is to the theoretical position to which it is expected to move. It is affected (or determined) by linearity error, hysteresis, abbe error, scale factor error and positioning noise, etc.

(see also validity) The extent to which a measurement, or an estimate based on measurements, represents the true value of the variable being measured.

the measure of how close an experimental value is to the true value.

Degree of conformity of a measure to a standard or true value; in other words, how close a predicted or measured value is to the true value.

In firearms using single projectiles at a given distance, is the measure of the dispersion of the group of projectiles fired. The optimum would be one hole no larger in diameter than a single projectile.

Closeness of agreement between the result of a measurement and the (conventional) true value of the measurement. Note 1. Use of the term precision for accuracy should be avoided. Note 2. True value is an ideal concept and, in general, cannot be known exactly. (Metrology, 1984)

Extent to which a measurement agrees with the accepted or correct value for that quantity, based on careful measurements by many people. Compare precision.

The characteristic of a measurement that tells how close an observed value is to a true value.

Degree to which an estimated, observed, or calculated value approaches the actual or true value (or what is believed to be the actual or true value).

The degree with which an instrument measures a variable in terms of an accepted standard value or true value; usually measured in terms of inaccuracy but expressed as accuracy; often expressed as a percentage of full-scale range.

Conformity with a standard or correctness in measurement. Accuracy relates to the quality of a result and is distinguished from precision which relates to the quality of the operation by which the result is obtained.

Quantity referring to the differences between the mean of a set of results or an individual result and the value which is accepted as the true or correct value for the quantity measured. Gold, Loening, McNaught and Sehmi, 1987 RT precision.

The extent to which a measurement agrees with the true value of the quantity being measured.

Indicates how closely an analytical or assay procedure approaches the true value for a particular sample. (Note that this requires knowing what the true value is.)

Refers to a measurement of the average correctness of data or an equation. See variance.

The discrepancy between the true value and the result obtained by measurement.

The degree of agreement between a measured value and a true, expected value.

Precision in the measurement of quantities and in the statement of physical characteristics. Accuracy is typically expressed in terms of error as a percentage of the specified value (e.g., 10 volts ± 1%), as a percentage of a range (e.g., 2% of full scale), as parts (e.g., 100 parts per million) or with absolute tolerances (e.g., 6.7kg ± 0.1kg).

The degree of agreement of a measured value with the actual expected value.

The degree of freedom from error. Accuracy is often confused with precision, which refers to the degree of preciseness of a measurement.

The degree of freedom from error. The total error compared to a theoretically true value. Contrast with and see precision for an example.

The degree of agreement between an individual measurement or average of measurements and the accepted reference value of the quantity being measured. See also precision.

the closeness of a measured value to the known "true" value of the measurand.

(of a test). The proportion of correctly classified patients based on the test and its threshold. The proportion of true positive classifications plus the proportion of true negative classifications. [See prevalence, sensitivity, specificity

difference between the actual value and the measured or expected value.

Freedom from error. Accuracy contrasts with precision; e.g., a four- place table, correctly computed, is accurate; a six-place table containing an error is more precise, but not accurate.

The extent to which results of a calculation or the readings of an instrument approach the true values of the calculated or measured quantities.

The difference between a set of representative values and the actual values. The accuracy of a point location would be the difference between the point's coordinates in the GIS and the coordinates accepted as existing in the real world.

The measure of a bullet's precision; the term describing a firearm's ability to shoot consistently where aimed.

Refers to how well your measurement of an object or phenomenon reflects its actual state. For example, it is important to have an accurate measurement of your feet in order to select well-fitting shoes. (See also Bias, Precision and Validity.)

the quality of nearness to the truth or the true value; "he was beginning to doubt the accuracy of his compass"; "the lawyer questioned the truth of my account"

(mathematics) the number of significant figures given in a number; "the atomic clock enabled scientists to measure time with much greater accuracy"

The degree to which an indicated value matches the actual value of a measured variable. In instrumentation, the ratio of the error to the full-scale output, usually measured as + ___ percent of full-scale output.

condition or quality, of an action, of being correct, true, or exact. Accuracy is typically a judgment by a verbal community about an action, not a property of the action itself. Accuracy differs from effectiveness. Accuracy also forms one of the defining properties of fluency.

This is the deviation between the actual position and the theoretical position of each bit edge. The base accuracy of an encoder is traceable to the encoding disc. Accuracy is different from and is not directly related to resolution.

The degree of precision. Usually expressed, in terms of error, as a percentage of the specified value, or as a percentage of a range.

Degree of conformity of a measured value to an accepted standard value; or closeness of a reading or indication of a sensor to the actual value of the quantity being measured.

A paternity test is considered accurate when proper procedures are followed to ensure that the results of the test are correct. At GeneSys, each sample is independently tested two times and the data are compared for consistency before reporting. The test results, reported as allele sizes, are objective measurements and are reliable, reproducible, and accurate.

A measure of the difference between expected position and actual position of a motor or mechanical system. Motor accuracy is usually specified as an angle representing the maximum deviation from expected position.

degree of conformity with a standard, or the degree of correctness attained in a measurement. Accuracy relates to the quality of a result, as distinguished from precision.

Indicates how well a scale displays the correct results. Accuracy is the ability of the scale or balance to display a value that matches the ideal value for a known weight.

a measure of how close the results of an experiment are to the true value; a measure of the correctness of the result.

In mapping, the reduction of positional and attribute errors based on information sources and data input instruments. Data precision must reflect, not exceed its accuracy.

Quantity defining the limit that errors will not exceed. When applied to flow meters, accuracy is specified in either % of full scale or % of rate.

A measure of the precision with which genetic merit is predicted. Accuracy ranges from .01 (low) if no information is available, to .99 (high) if there is a large amount of performance information on the individual and its relatives. It is an expression of the reliability of the EPD. Accuracies indicate the level of confidence that the predicted EPD is near the true genetic potential of that animal. Accuracies are not available at this time.

Closeness of a measured value to the real value (see precision).

The difference between the reading of an instrument and the true value of what is being measured, expressed as a percent of full instrument scale.

The degree to which a measurement, or an estimate based on measurements, represents the true value of the attribute that is being measured. (See also Precision and Validity which are the two components of "Accuracy")

Accuracy normally refers to conformity of an indicated value to an accepted standard value. There is no indication in switch products; thus, instead, the term repeatability is used as the key performance measure.

A measure of how well one set of data matches another, particularly how well a set of predictions match the actual measures. Accuracy is not a simple subject, it is not the opposite of error and there are many ways to calculate accuracy with widely different results. The typical calculation of accuracy is 1-(abs(Predicted-Actual)/Actual), however this calculation breaks down if the Actual is zero (0). Another example of an accuracy calculation is "Relative Accuracy" which is 1-(abs(Predicted-Actual)/(Range of Actual).

A computed indicator of the system's ability to place the correct mate within a specified position on the candidate list as a result of the matching process.

A measure of the similarity of an instrument reading to the actual value for that reading. The accuracy of temperature measurement indicators on thermal imagers is affected by emissivity, the distance from the object, the angle of the object and a number of other factors.

the agreement between a mean measured value and a true or accepted value as quantified by error. Related to determinate errors and quantified by bias.

The extent to which the measured value of a quantity agrees with the accepted value for that quantity.

1. If applied to paper maps or map databases, degree of conformity with a standard if accepted value. Accuracy relates to the quality of a result and is distinguished from precision. 2. If applied to data collection devices such as digitizers, degree of obtaining the correct value.

The degree of agreement between an observed value and an accepted reference value. Accuracy includes a combination of random error (precision) and systematic error (bias), components which are due to sampling and analytical operations (NELAC, 2001). Note: Because the true toxicity (unlike, for example, mass) of a material cannot be determined this term is generally not considered applicable to toxicity testing. Consequently "true" values for laboratory evaluation studies are typically mean or median values of participating labs.

Those attributes of a system that provide the required precision in calculations and outputs.

the closeness by which a set of measurements approaches the true value; if the true value is not known the accuracy is taken to be the realistic estimation of that closeness.

Accuracy is the maximum allowable set point deviation of a unit from the actual value under one given set of environmental and operational conditions.

Related to the incremental encoding disk. It is the difference between the theoretical position of one increment or bit edge and the actual position of the edge.

The measure of the correctness of data, as given by the difference between the measured value and the true or standard value.

Degree of agreement between average predictions of a model or the average of measurements and the true value of the quantity being predicted or measured.

A measure of closeness of agreement between a test result and an accepted reference value. EXAMPLE: If you have a standardized reference material at a known value (such as 180 mg/dl of cholesterol), accuracy measures how close the result of the test you are using will get to the known value. You may have a test that is very precise yet very inaccurate, which would be the case if your device measures 180 mg/dl of cholesterol reproducibly as 240 mg/dl.

The degree of closeness of the determined value to the nominal or known true value under prescribed conditions. This is sometimes termed trueness.

the deviation from the absolute truth this figure should include linearity, repeatability and calibration uncertainty.

Measure of the difference between the commanded and the actual position of the motor or a mechanical system.

the closeness of an estimate (or measurement) to its true (but unknown) value

is the degree to which information on a map or in a digital database matches true or accepted values. Accuracy is an issue pertaining to the quality of data and the number of errors contained in a dataset or map. In discussing a GIS database, it is possible to consider horizontal and vertical accuracy with respect to geographic position, as well as attribute, conceptual, and logical accuracy. The effect of inaccuracy and error on a GIS solution is the subject of sensitivity analysis . Accuracy, or error, is distinguished from precision , which concerns the level of measurement or detail of data in a database.

These terms are often used interchangeably to indicate how well a scale displays the correct results. Accuracy is the ability to display a value that matches the ideal value for a known weight.

limit tolerance established after taking the probable errors of hysteresis, nonlinearity, nonrepeatability, and temperature effects into consideration

The quality of closeness to a specified value under stated reference conditions. Accuracy is quantitatively expresses by uncertainty. Accuracy, intrinsic: The limit of the accuracy of an instrument when used under reference conditions. Accuracy is expresses in percentage of the fiducial value. This concept of accuracy is concerned with the intrinsic qualities of the instrument as opposed to the variation in indication that may arise when the instrument is used under conditions other than the reference conditions. Intrinsic accuracy is the uncertainty of the instrument in the "as received" condition, without the applications of corrections from a chart, curve or tabulation.Accuracy, rated (class): The assigned classification, which represents the value of uncertainty that the intrinsic accuracy of the instrument will not exceed.

The closeness of approach of a measured dimension to the "true" or nominal value specified. Since both the "true" value and the measured dimension can only be approximated within some tolerance limits rather than exactly determined, the most probable value derived, examined for sources of error, is used as the "true" value. See Precision.

A measure of the difference between expected position and actual position of a mechanical system. As it relates to linear travel, accuracy is usually specified as linear inches per inch.

In this project, the ability of the archaeological predictive model to correctly predict site presence in a parcel of land (see Precision).

The variation between the specified delay time and the Actual Time value, given in percent of specified delay. Actual Time - Specified Delay Time) / Specified Delay Time)) x100.

the degree to which a measurement (e.g., the mean estimate of a treatment effect) is true or correct. An estimate can be accurate, yet not be precise, if it is based upon an unbiased method that provides observations having great variation (i.e., not close in magnitude to each other). (Contrast with precision.)

Accuracy is how close a numerical measure is to its actual value.

The degree to which a sample statistic would correspond to the population parameter it is meant to estimate if there were no random error. Accuracy is high when bias is low.

The extent to which a measurement is close to the true value.

The term accuracy refers to how close we are to the nominal value. In the past we have used this term to indicate error in a measurement device. For instance, the accuracy of a standard cell is plus or minus 0.01 percent. Use of the word accuracy in this sense is incorrect because what we mean is the inaccuracy or error is plus or minus 0.01 percent. However, this is still a common method of describing accuracy?s. To remedy this practice, the National Bureau of Standards has dropped the term accuracy, when used in this respect, and uses instead the term "uncertainty."

The difference between a measured value of a feature and its true value on the Earth's surface.

describes the centrality of data groupings around a true value. (see precision)

Accuracy is the degree of error between the intended, specified, or nominal property value and actual value. Typically used to define the performance envelope of a production lot of parts about the specified nominal. Normally used to relate single-event performance of multiple parts. Compare to PRECISION.

precision of a performance with respect to the music selected, whether from a written score or aural transcription

With regard to spatial data, the degree of conformity with a standard, whether absolute or relative. Accuracy relates to the quality of the result so that higher accuracy implies that a measurement is nearer the truth.

The most difficult PDR fundamental. The technique of locating a tool tip precisely where it is needed.

Difference between expected position and achieved position.

The degree of uncertainty with which a measured value agrees with the ideal values. Accuracy class of instrument transformers are defined by the requirements of ANSI standard number C57.13. Standard metering accuracy classes are 0.3, 0.6 and 1.2

The closeness of a sample estimate to the true population value.

The degree of freedom from error or the degree of conformity to a standard.

An expression describing the ability of a measuring instrument to show the true value of a measured quantity. It is generally expressed as the magnitude of the total error expected in the measurement. It is usually given as a percent of full scale reading of the measuring instrument.

The difference between the actual and measured position.

A degree of exactness. In project work, usually expressed as a range part icularly in connection with estimate s of cost and time. [D02349] RMW

(1) Percentage of words correctly transcribed by a handwriting recognition engine; (2) Error bounds of a coordinate measurement, relative to a physical reference frame

The freedom from mistake or error: correctness. The degree of conformity to some recognized standard value. For purposes of the ZIMS Project, accurate data captured from user input, system interfaces or external data feeds is properly validated.

The degree to which the mean of a sample approaches the true mean of the population; lack of bias.

The closeness of a measurement to its true value.

A measurement of deviation from the CAD data. Accuracy is dependent on the process used to make the rapid prototype.

A criterion used in evaluating the quality of information. Accuracy measures the degree to which information sources are free from mistakes and errors. An encyclopedia which said that the Oakland Raiders won the Super Bowl in 2000 would be giving inaccurate information.

How close an estimate is to the parameter being estimated

a quantitative measure of the magnitude of error [ IEEE 90].

The difference between a value appearing on the website and the actual value of that item. Data values may be affected by rounding and estimation, as well as by other quality issues. The dataset information (metadata) will give full details. Note that values may be published to a high resolution, such as two decimal places, without being accurate to that level.

The degree of conformity of the indicated (measured) value to the true value. The accuracy of a venturi based on empirical data varies with the diameter and method of construction. By individual calibration the accuracy can be +/- 1/2%.

Degree of conformance of a value to a recognized, accepted standard value. Accuracy is expressed as the maximum positive and negative deviation from the standard for specific conditions, usually expressed as the inaccuracy as a percent of the value, instrument range, or full-scale value. It includes causes of inaccuracy, including linearity, repeatability and hysteresis.

Correct preparation of all documents.

The ability of an airgun to consistently Group all its shots close together at a given distance under optimal conditions. Accuracy does not take into account human error or environment conditions.

The degree of conformance between the estimated or measured position, time, and/or velocity of a GPS receiver and its true time, position, and/or velocity as compared with a constant standard. Radionavigation system accuracy is usually presented as a statistical measure of system error and is characterized as follows: Predictable - The accuracy of a radionavigation system's position solution with respect to the charted solution. Both the position solution and the chart must be based upon the same geodetic datum. Repeatable - The accuracy with which a user can return to a position whose coordinates have been measured at a previous time with the same navigation system. Relative - The accuracy with which a user can measure position relative to that of another user of the same navigation system at the same time.

The difference from the precise value of the intended velocity or position.

Difference between the average result of a measurement with a particular instrument and the true value of the quantity being measured.

The degree to which the measured leak rate agrees with the induced leak rate on the average. If a system is accurate, it has a very small or zero bias.

The measure of precision in consistently obtaining a desired result. In shooting, the measure of a bullet's or gun's ability to place all shots close to the same point.

degree of conformity with a standard. Accuracy relates to the quality of a result, and is distinguished from precision, which relates to the quality of the operation by which the result is obtained. see Accuracy and Precision for further information.

Closeness of the agreement between the result of a measurement and a true value of the measurand.

A measure of how close a regulator can keep downstream pressure (P2) to the setpoint. Regulator accuracy is expressed in percent droop or proportional band.

A quality of that which is free of error. Contrast with precision.

the closeness of results of observations, computations or estimates to the true values or the values accepted as being true.

The ability of a test device to produce a reading that matches the known value for the sample.

A measure of how close an estimate of a GPS position is to the true location.

How close a fix comes to the actual position.

Compare with precision and trueness. Accuracy is the correctness of a single measurement. The accuracy of a measurement is assessed by comparing the measurement with the true or accepted value, based on evidence independent of the measurement. The closeness of an average to a true value is referred to as "trueness".

Correlation between an animal's unknown actual breeding value and a calculated estimated breeding value.

Accuracy is how close to the actual value you are. For example, if the number you are representing is 4 and you say it's 3, you are inaccurate by 1.

Degree of conformity of an indicated value to a recognized standard value, or ideal value.

free from errors and mistakes

The degree of agreement between a measured value and the true value; usually expressed as +/- percent of full scale.

Level of agreement between a test value and the expected value for a reference standard of known activity or titre..

The ability of the test result to measure the "true" quantity of a drug; if any, in a urine specimen.

The extent to which a machine vision system can correctly measure or obtain a true value of a feature. The closeness of the average value of the measurements to the actual dimension.

The degree of conformity of an indicated value to an accepted standard value, or ideal value. See accuracy rating, measured accuracy.

The extent to which a measurement of a quantity agrees with its true value.

Content that is valid and without errors of fact, interpretation, or judgment.

The closeness of an indication or reading of a measurement device to the actual value of the quantity being measured. Usually expressed as ± percent of full scale output or reading.

The measure of precision in consistently obtaining a desired result. In shooting, the measure of a bullet's or gun's precision in grouping all shots close to the center of impact.

The difference between the observed average value of the measurements and the true value.

Absolute accuracy is defined as the expected maximum error in the geographical position as computed by the DGPS user equipment within some specified statistical limit. For DGPS systems the limit is usually the horizontal two dimensional error measure called 2 drms (twice the root mean square error). For the Canadian DGPS system, the error limit is 95%, which is the minimum 2 drms value for bivariate normal error distribution. The position accuracy of the DGPS Service will be 10 meters, 95% of the time; or better in all specified coverage areas (assuming the full 24 GPS satellite constellation and a HDOP  2.3).

A measure of the closeness of agreement of a measured test result obtained by the analytical method to its theoretical true (or accepted reference) value. This is relevant only for calibration-curve based applications where a purified or relative reference standard material is available to quantify the analyte levels in test samples.

The difference between the "measured" and "true" values. The degree of statistical agreement (usually at the 95% confidence level) between a measured value and the true value, or the certainty or "sureness" with which a measured value is known.

The closeness of a measured value to a true value.

A measure of how close a count or measurement is to the true value; a measure of the correctness of a result.

The closeness of agreement between an observed value and an accepted reference value. Also see Precision.

The combined error of nonlinearity, repeatability and hysteresis in terms of percent of full scale output.

The combined error of non-linearity, repeatability, and hysteresis expressed as a percentage of the full-scale output.

The deviation between actual value and the expected, ideal value. Absolute accuracy specifies the degree of accuracy that exists in comparison to primary or secondary standards under all specified operating conditions. Typical accuracy is sometimes called relative or nominal accuracy. It assumes that a fixed set of operating conditions exist, and that the instrument parameters statistically average to provide a typical operating accuracy throughout its measuring range.

The maximum expected difference between the actual and a desired position for a given input. Highly dependent on method of actual position measurement.

The degree of conformance of measurement of a model, standard or true value. Expressed as a percentage of specified value.

The ratio of the error to the full-scale output or the ratio of the error to the output, as specified, expressed in percent.

The closeness to the truth of measurement data or station coordinates. Accuracy can only be determined by a comparison against an independent determination or measurement of the data or coordinates. "Check" surveys are often carried out independently of the main survey of an area to detect inaccuracies in the station coordinates.

In a statistical sense, the success of estimating the true value of a quantity. Sometimes defined the same as precision, but not here. See Precision.

1. The degree to which a measured value is similar to an actual value. 2. The extent to which vision sensors can correctly measure and obtain a true value of a feature. A combination of imager resolution, pixel resolution and field of view is used to describe the match level of an inspection.

(Measurement and Inspection) The difference between indicated value and actual value, at room temperature. In most cases, the accuracy is comprised of two main sources of error: the resolution and the linearity.

The maximum deviation that can be expected between the meter reading and the actual value being measured, under specified conditions.

A state characterized by measurements or estimates clustering tightly about the true value.

The combination of the error of nonlinearity, repeatability and hysteresis, expressed as a percentage of full scale output.

A statement that is used to define the largest allowable error in a device or system. It is an indication of how close measured values are to true values. It can be expressed in both measured units and in percentages.

How close a measured value is to its "true" value if it could be measured without any errors. Experiments need to be designed to give the best possible accuracy.

Does the site have any obvious errors in spelling, grammar or other areas? -- Do you detect any bias in the material

The degree of agreement of a measurement (X) with an accepted reference or true value (T); usually expressed as the difference between the two values (X – T), or the difference as a percentage of the reference or true value (100[X – T]/T), and sometimes expressed as a ratio (X/T).

(1) In common usage, accuracy is the quality of being true or correct. (2) As a measure of diagnostic performance, accuracy is a measure of how faithfully the information obtained using a medical imaging agent reflects reality or truth as measured by a truth standard or gold standard. Accuracy is the proportion of cases, considering both positive and negative test results, for which the test results are correct (i.e., concordant with the truth standard or gold standard.) Accuracy = (a+d)/N = (TP+TN)/(TP+FP+FN+TN).

Refers to closeness of a measurement to the true value.

Also known as Precision Landing, this is a competition discipline in which the skydiver attempts to land on an established target. At the National level the target is 3 cm in diameter, about the size of a quarter. Accuracy landings of various difficulty, from 20 meters to 2 meters, are required for USPA licenses. See the SIM for details.

Freedom from error in the data.

How close a measurement is to being correct. For gravitational acceleration near the earth, g = 9.7 m/s2 is more accurate than g = 9.532706 m/s2. See Precision.

A measurement of how precise a GPS location is relative to the actual location.

See Measurement Uncertainty.

(1) The ability to hit the target. (2) Conformity of a measured value to the actual value of the sample.

A measure of the similarity of an instrument reading to the actual value for that reading. Instrument accuracy is affected by many things -instrument drift, environment, temperature, time, operator expertise, etc.

Closeness of results of observations, computations, or estimation of spatial features to their true value of position.

How closely an instrument measures the true or actual value of the process variable being measured or sensed.

The agreement of the test result with the true value of the sample.

the extent that a measurement agrees or compares with an accepted value or standard.

the ability of a robot to move to a specified X, Y and Z value in space.

The combined error of nonlinearity, repeatability, and hysteresis expressed as a percent of full scale output.

The validity of data measured with respect to an independent source of higher reliability and precision.

Correctness. In conformation with a standard.

Accuracy is an important factor in assessing the success of data mining. When applied to data, accuracy refers to the rate of correct values in the data. When applied to models, accuracy refers to the degree of fit between the model and the data. This measures how error-free the model's predictions are. Since accuracy does not include cost information, it is possible for a less accurate model to be more cost-effective. Also see precision.

The determination of whether an element width or intercharacter gap width (if applicable) differs from its nominal width by more than the printing tolerance.

The deviation of the actual dimension from the nominal dimension as described by tolerances. For monorail systems, accuracy is defined as the parallel deviation of the reference surfaces within given tolerances. See Running accuracy and Dimensional accuracy.

The ability to reach the target.