Glossary of Terms

All complex subjects have their own terminology that sometimes makes it hard for new people to break into the field. This sometimes includes uncommon words, but more often than not a subject will have very specific meanings for common words - the discussion of errors vs mistakes in this video is a good example of this.

This glossary is a reference of some of the uncommon terms and specific definitions of more common words that you will encounter throughout Data Tree and your broader dealings with data. 

Many of these definitions come from the course materials and experts that helped develop Data Tree. Others come from the CASRAI Dictionary. Those definitions are kindly made available under a Creative Commons Attribution 4.0 International License.

Browse the glossary using this index

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Natural Capital

Can be defined as the world's stocks of natural assets which includes soil, water, air, flora and fauna.


In the electromagnetic spectrum, near-infrared lies between red visible light and infrared. See also Infrared.


A programme of seven NASA missions of Earth Observation satellites, starting in 1964. Nimbus is Latin for rain cloud.


Noise in data is meaningless data or unexplained variation in data which might be due to instrument errors, corruption or other issues. Noise disguises and/or distorts the underlying data which make it harder to analyse, just as noisy environments make it more difficult to hear the sound on which you wish to focus.

Normal distribution

The normal distribution is used to model some continuous variables. It is a symmetrical bell shaped curve that is completely determined by two parameters. They are the distribution (or population) mean, μ, and the standard deviation, σ.

Numerical Variable

Refers to a variable whose possible values are numbers (as opposed to categories).