Pooled standard deviation

{
  "id": "MLC-T-CHM-009262",
  "term": "Pooled standard deviation",
  "field": "Chemistry",
  "definition": "A statistical measure that combines the standard deviations from two or more independent samples, assuming that these samples are drawn from populations with the same underlying variance. This calculation provides a single, more precise estimate of the common standard deviation across the groups. It is frequently used in hypothesis testing, such as in a two-sample t-test, to increase the power of the statistical analysis.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "precision",
    "relative standard deviation",
    "standard deviation"
  ],
  "references": [
    "PAC, 1981, 53, 1805. 'Assignment and Presentation of Uncertainties of the Numerical Results of Thermodynamic Measurements' on page 1821 (https://doi.org/10.1351/pac198153091805)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/pooled-standard-deviation/"
}