Standard Deviation

{
  "id": "MLC-T-ENV-026545",
  "term": "Standard Deviation",
  "field": "Environment",
  "definition": "1. A measure of the spread, the square root of the variance; a statistic used with interval-ratio variables.\n\n2. A measure of the scatter of several sample values around their average. For a sample, the standard deviation (s) is the positive square root of the sample variance. For a finite population, the standard deviation (s) is where μ is the true arithmetic mean of the population and N is the number of values in the population. The property of the standard deviation that makes it most practically meaningful is that it is in the same units as the observed variable X. For example, the upper 95% probability limit on differences between two values is 2.77 times the sample standard deviation.\n\n3. Means the response associated with the BMR will be the background estimate plus or minus the product of the BMR times the standard deviation about the mean for the control data.\n\n4. The most widely used measure of dispersion of a frequency distribution, equal to the positive square root of the variance.\n\n5. A measure of spread or dispersion of a distribution. It estimates the square root of the average squared deviation from the distribution average, sometimes called the root-mean-square. Among all measures of dispersion, the standard deviation is the most efficient for normally distributed data. Also, unlike the range, it converges to a single value as more data from the distribution is gathered.\n\n6. A computed measure of variability indicating the spread of the data set around the mean. {ORD} {OPP} {OW/TSC} {OAR/OAQPS} {OECA} {ORCR}\n\n7. Measure of the spread, the square root of the variance; a statistic used with interval-ratio variables.\n\n8. Meaning given in § 1065.602. Note this is the standard deviation for a non-biased sample.\n\n9. The most widely used measure of dispersion of a frequency distribution, equal to the positive square root of the variance. (CDC 2005)\n\n10. Measure of spread or dispersion of a distribution. It estimates the square root of the average squared deviation from the distribution average, sometimes called the root-mean-square. Among all measures of dispersion, the standard deviation is the most efficient for normally distributed data. Also, unlike the range, it converges to a single value as more data from the distribution is gathered. (NIST/SEMATECH 2005b)\n\n11. Measure of dispersion or variation, usually taken as the square root of the variance. [RAIS 2004, SRA 2004]\n\n12. Response associated with the BMR will be the background estimate plus or minus the product of the BMR times the standard deviation about the mean for the control data.\n\n13. A computed measure of variability indicating the spread of the data set around the mean.\n\n14. Measure of the dispersion or imprecision of a sample or population distribution as expressed as the square root of the variance and has the same unit of measurement as the mean. The standard deviation is calculated as the square root of the variance. [EPA 240/R-02/005]\n\n15. Measure of the dispersion or imprecision of a sample or population distribution as expressed as the square root of the variance and has the same unit of measurement as the mean. The standard deviation is calculated as the square root of the variance.",
  "abbreviation": "s",
  "synonyms": [
    "SD"
  ],
  "subject": "Science and research",
  "references": [
    "Program Evaluation Glossary",
    "Radon Glossary of Terms",
    "Benchmark Dose Software (BMDS) Glossary of Terms",
    "CDC 2005",
    "NIST/SEMATECH 2005b",
    "Forum on Environmental Measurements (FEM) Glossary",
    "40 CFR 1065.1001 (CFR 2013)",
    "Thesaurus of Terms Used in Microbial Risk Assessment",
    "Environmental Sampling and Analytical Methods (ESAM) Program Glossary",
    "EPA 240/R-02/005"
  ],
  "url": "https://mlchart.com/terminology/environment/standard-deviation/"
}