Compositional data and their analysis: an introduction

A chapter In the book 'Compositional Data Analysis in the Geosciences: for theory to practice'. Compositional data are those which contain only relative information. They are parts of some whole. In most cases they are recorded as closed data, i.e. data summing to a constant, such as 100% - whole-rock geochemical data being classic examples. Compositional data have important and particular properties that preclude the application of standard statistical techniques on such data in raw form. Standard techniques are designed to be used with data that are free to range from -oo to +oo. Compositional data are always positive and range only from 0 to 100, or any other constant, when given in closed form. If one component increases, others must, perforce, decrease, whether or not there is a genetic link between these components. This means that the results of standard statistical analysis of the relationships between raw components or parts in a compositional dataset are clouded by spurious effects. Although such analyses may give apparently interpretable results, they are, at best, approximations and need to be treated with considerable circumspection. The methods outlined in this volume are based on the premise that it is the relative variation of components which is of interest, rather than absolute variation. Log-ratios of components provide the natural means of studying compositional data. In this contribution the basic terms and operations are introduced using simple numerical examples to illustrate their computation and to familiarize the reader with their use



Website:

http://sp.lyellcollection.org/content/264/1/1.full.pdf

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Date (Creation)
2006-01-01
Date (Publication)
2006-01-01
Date (Revision)
Citation identifier
https://www.mica-project.eu/ / MICA_B2-24

MICA WP3 2017-09-25T10:33:00 Record extracted from Batch 2 spreadsheet

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No additional information provided about the dataset
Purpose

Purpose for data generation is not known
Status
Completed
Point of contact
Organisation name Individual name Electronic mail address Role

The Geological Society of London

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Maintenance and update frequency
Not planned
dataCentre

  • MICA

MICA ontology (TemporalScheme)

  • Geological time

MICA ontology (DataScheme)

  • General descriptive information / Report / Trade association (Report)
Keywords

  • Requirement for data generation: Voluntary
Keywords

  • Method of data or information generation: Academic research

GEMET Concepts

  • Exploration

GEMET Concepts

  • Geochemical

GEMET Concepts

  • Sciences dealing with the composition, structure, origin of the Earth's rocks

MICA ontology (DomainScheme)

  • Detailed geochemistry

MICA ontology (DomainScheme)

  • Regional geochemistry
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Language
English
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  • Economy
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Individual item (e.g. a one-off academic paper or single website)

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Data uncertainty
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Are any uncertainty measures provided (e.g. standard errors, confidence intervals, etc.)?
Pass
Yes

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Quality assurance procedures
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Are quality assurance procedures described?
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Yes

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Title

Information generation methods
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Are data or information generation methods formally described?
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Yes

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Reviewed by: British Geological Survey
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Record validation
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No

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Title
Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
Date (Publication)
2010-12-08
Statement

Organisation source implies that information should be of good quality

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Metadata language
English
Character set
MD_CharacterSetCode_utf8
Hierarchy level
Non geographic dataset
Date stamp
2024-11-07
Metadata standard name

ISO19115
Metadata standard version

2003/Cor.1:2006
Metadata author
Organisation name Individual name Electronic mail address Role

British Geological Survey

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