Precision

{
  "id": "MLC-T-ENV-021881",
  "term": "Precision",
  "field": "Environment",
  "definition": "1. The quality of being reproducible in amount or performance. With models and other forms of quantitative information, precision refers specifically to the number of decimal places to which a number is computed as a measure of the \"preciseness\" or \"exactness\" with which a number is computed.\n\n2. A measure of the closeness of agreement among individual measurements.\n\n3. The ability of an instrument to measure a process variable and to repeatedly obtain the same result. The ability of an instrument to reproduce the same results.\n\n4. The exactness of a question's wording or the amount of random error in an estimate.\n\n5. A measure of mutual agreement among individual measurements of the same property, usually under prescribed and similar conditions. Most desirably expressed in terms of the standard deviation, but can be expressed in terms of the variance, pooled estimate of variance, range, relative percent difference, or other statistic.\n\n6. A measure of agreement among repeated measurements of the same property under identical, of substantially similar, conditions; expressed generally in terms of the standard deviation.\n\n7. A measure of mutual agreement among individual measurements of the same property, usually under prescribed similar conditions, expressed generally in terms of the standard deviation.\n\n8. The level of agreement among multiple measurements of a characteristic.\n\n9. The reproducibility of a measurement; the closeness of each of a set of similar measurements to the arithmetic mean of that set.\n\n10. A measure of the reproducibility of a measured value under a given set of circumstances.\n\n11. The degree to which replicate measurements of the same attribute agree or are exact. \"The degree to which a set of observations or measurements of the same property, usually obtained under similar conditions, conform to themselves; a data quality indicator\" (QAMS 1993, 16).\n\n12. The degree to which a measurement (e.g., the mean estimate of a treatment effect) is derived from a set of observations having small variation (i.e., close in magnitude to each other). A narrow confidence interval indicates a more precise estimate of effect than a wide confidence interval. A precise estimate is not necessarily an accurate one.\n\n13. The consistency of measurement values quantified by measures of dispersion such as the sample standard deviation. Precision must be defined in context e.g., for a certain analyte, matrix, method, perhaps concentration, lab or group of labs. {ORD} {OW/EAD} {OPP} {OW/TSC} {OAR/OAQPS} {OECA} {ORCR}\n\n14. A quantitative representation of the degree of accuracy necessary for or associated with a particular action.\n\n15. Two times the standard deviation of a set of measured values of a single zero or reference quantity.\n\n16. Measure of the reproducibility of a measured value under a given set of circumstances. [EPA 1997a, EPA 2004]\n\n17. Measure of the reproducibility of the predictions of a model or repeated measurements, usually in terms of the standard deviation or other measures of variation among such predictions or measurements. [FAO/WHO 2003b]\n\n18. Quality of being sharply defined or stated. One measure of precision is the number of distinguishable alternatives from which a measurement wan selected, sometimes indicated by the number of significant digits in the measurement. Another measure of precision is the standard error of measurement, the standard deviation of a series of replicate determinations of the same quantity. See also measurement, problems with terminology. Statistics: Precision is defined as the inverse of the variance of a measurement or estimate. [Last 1983]\n\n19. Standard deviation of replicated measurements. [40 CFR 86.082-2 (CFR 2018)]\n\n20. The consistency of measurement values quantified by measures of dispersion such as the sample standard deviation. Precision must be defined in context e.g., for a certain analyte, matrix, method, perhaps concentration, lab or group of labs.\n\n21. A measure of how closely values from replicate measurements of a sample agree with each other. Usually expressed as standard deviation, variance, or range in either absolute or relative terms. A data quality indicator.",
  "subject": "Policy and guidance",
  "references": [
    "Modeling Glossary",
    "Waste and Cleanup Risk Assessment Glossary",
    "Drinking Water Technical & Legal Terms",
    "Program Evaluation Glossary",
    "Radon Glossary of Terms",
    "Guidance for Quality Assurance Project Plans",
    "Great Lakes: Quality Management Training - Data Review Glossary; Great Lakes: Quality Management Training - Quality Glossary",
    "Great Lakes Quality Mgmt Plan Glossary",
    "Environmental Geophysics Glossary",
    "Exposure Factors Handbook: Glossary; EPA 1997a, EPA 2004",
    "Environmental Modeling and Assessment Program (EMAP) Master Glossary",
    "NLM/NICHSR 2004",
    "Forum on Environmental Measurements (FEM) Glossary",
    "National Cancer Institute Thesaurus",
    "40 CFR 1065.1001 (CFR 2013)",
    "Thesaurus of Terms Used in Microbial Risk Assessment",
    "40 CFR 86.1803-01 (CFR 2018)",
    "EPA 815-B-04-001; QA Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/precision/"
}