H0
Abbreviation with 2 meanings
| Stands for | Null hypothesis |
|---|---|
| Meanings | 2 |
| Categories | Units & Measurements, Science & Engineering |
H0 has two meanings. It stands for Null hypothesis (statistics) or Hubble constant (astronomy & Space).
Meanings of H0 at a glance
| # | H0 stands for | Context |
|---|---|---|
| 1 | Null hypothesis | Units & Measurements › Statistics |
| 2 | Hubble constant | Science & Engineering › Astronomy & Space |
1. Null hypothesis
Units & Measurements · Statistics Abbreviations
The default claim in a statistical test, usually of no effect or no difference, written H₀ and read "H-naught". The data are examined to see whether they provide enough evidence to reject it.
Example: H0: the mean recovery time is the same for both treatments.
Failing to reject H0 does not prove it true; the study may simply lack power. Rejecting a true H0 is a Type I error, with probability α (often 0.05), and failing to reject a false one is a Type II error. Modern hypothesis testing blends ideas from Ronald Fisher with those of Jerzy Neyman and Egon Pearson.
2. Hubble constant
Science & Engineering · Astronomy & Space Abbreviations
Present-day expansion rate of the universe, the speed at which galaxies recede per unit of distance, expressed in kilometers per second per megaparsec. Its inverse gives a rough age of the universe, and measurements currently cluster around 67-73 km/s/Mpc.
Example: Using Cepheids and supernovae, the team measured H0 at 73 km/s/Mpc.
Edwin Hubble published the velocity-distance relation in 1929, though Georges Lemaître had derived it in 1927; the IAU recommended renaming Hubble's law the Hubble-Lemaître law in 2018. Usually written H with a subscript zero, read "H-naught." Despite its name, the value changes over cosmic time.
Related abbreviations
More statistics abbreviations
- FDR – False discovery rate
- FPR – False positive rate
- GARCH – Generalized autoregressive conditional heteroskedasticity
- GLM – Generalized linear model
- H1 – Alternative hypothesis
- HR – Hazard ratio
- ICC – Intraclass correlation coefficient
- iid – Independent and identically distributed
See all 88 statistics abbreviations →