# What does mean “background” in statistics or geostatistics? [closed]

somebody told me it was a bottom value , but I still don't get the whole picture.

• Can you give an example of where it is used? – Gimelist May 15 '17 at 22:54

## 1 Answer

Note: Since there is more than one use case of background in geostatistics, I will pick only one. If this is not the right background you are looking for, please edit and clarify your question.

Answer: A data point can be given by an absolut value A or a background value B plus a deviation D where B + D = A.

Example: If you are looking at a map showing the mean temperature of year X, you can look at the absolute field A or on its deviation D from the climatological year mean temperature of 1961-1990 B. Sometimes the latter tells you more, depending on what you are interested in. Additionally, analyses and statistical methods are often applied to the deviation field instead of the absolute field to identify patterns.

• Not sure why this was put on hold. It's a good question about a confusing subject. – geogaffer May 17 '17 at 1:23
• I work with geologists where I'm explaining this quite often. Background is definitely not just the lowest values. Especially because you can have negative anomalies. The short answer is "background" characterizes the data/signal that is not anomalous. Therefore understanding background is an important step in understanding what an anomaly is. If this gets taken off hold I can help with a more complete answer and references. – geogaffer May 17 '17 at 2:03
• FuzzyLeapfrog: your answer is closer to explaining residual than background. In the usual geological meaning a sample either belongs to a population which is background or not. In that context anomalies are not background plus something. They are sourcing from a different, typically less common population which is not background. Your description is more like EM noise and signals where more continuous mixing takes place. – geogaffer May 17 '17 at 4:07
• "Background is definitely not just the lowest values." I agree and never maintained the contrary in my answer. Since OP did not clarify their question, it's hard to say what kind of background they are looking for. Could also be the background field in the sense of kriging etc. ... I agree that this question should not be on hold. – FuzzyLeapfrog May 17 '17 at 4:39
• No! Didn't mean to imply you did! It was in the originators comment. I have a feeling a "Krigger" would ask a more specifically worded question. I can see several good questions spinning off this one too. – geogaffer May 17 '17 at 5:23