A standardized mean difference is a quantitative measure of the magnitude of difference between two groups or conditions, expressed in units of standard deviation. It is calculated by subtracting the mean of one group from the mean of another and dividing by a pooled standard deviation, producing a unitless effect size that enables comparison across studies using different measurement scales. The construct persists through statistical practice, meta-analysis methodology, and the conventions of quantitative research reporting. [formal: standardized mean difference | substrate: mind | horizon: hours | explicit: yes | epoch: 0.42]
Accepted ontology entry
standardized mean difference
A standardized mean difference is a quantitative measure of the magnitude of difference between two groups or conditions, expressed in units of standard deviation. It is calculated by subtracting the mean of one group from the mean of anot…
Definition
Why it is in scope
A statistical measure expressing the difference between two group means in units of standard deviation. Human-made through meta-analytic practice, persists through statistical reporting standards and computational methods (Cohen's d, Hedges' g) that standardize effect reporting across studies.
Names and aliases
- standardized mean differenceen · CANONICAL
Relations from this entry
- cmrxj3acr03cmsoacx73fal1oDERIVED_FROM →
Standardized mean difference is derived from statistics: the concept of standardizing a difference using statistical parameters (standard deviation). Statistics as a discipline existed first and provided the tools SMD uses.
- cmsmr9nmp023q1q13rk6xnpgeINSTANCE_OF →
Direction tested (specific→general): standardized mean difference IS A specific kind of statistical measure — it quantifies the difference between two means in standard deviation units. A competent speaker would call it 'a statistical measure.' Nearest kind check: statistical measure is the general category for any metric that quantifies data.
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Record identity
- Created
- Aug 9, 2026, 5:49 PM UTC
- Content hash
- 7c7f5cf7f18ca21e9b4a6dec3dc06ead90ff6cbcb316fa8950540167bd09a8e4