changingminds.org

How we change what others think, feel, believe and do

| Menu | Quick | Books | Share | Search | Settings |

Covariance

 

Explanations > Social ResearchStatistical principles > Covariance

Description | Example | Discussion | See also

 

Description

Deviation of a variable in a sample is its value minus the sample mean (x-bar).

dev(x) = x - x-bar

Covariance is a measure of how much the deviations of a pair of variables match.

cov(x,y) = SUM( (x - x-bar)*(y - y-bar) )

A higher number for covariance indicates strong matching. A negative number indicates weak matching.

Example

In the first table below, x and y go up and down together. In the second table, they are a lot less similar.

 

x y x-xbar y-y-bar (x-xbar)*
(y-ybar)
2 1 -2.57 -3.86 9.92
5 6 0.43 1.14 0.49
4 3 -0.57 -1.86 1.06
3 1 -1.57 -3.86 6.06
5 8 0.43 3.14 1.35
6 9 1.43 4.14 5.92
7 6 2.43 1.14 2.78
Mean of above
(xbar, ybar):
  Covariance
(sum of above):
4.57 4.86     27.57

 

x y x-xbar y-y-bar (x-xbar)*
(y-ybar)
2 8 -2.57 3.57 -9.18
5 2 0.43 -2.43 -1.04
4 7 -0.57 2.57 -1.47
3 8 -1.57 3.57 -5.61
5 1 0.43 -3.43 -1.47
6 2 1.43 -2.43 -3.47
7 3 2.43 -1.43 -3.47
Mean of above
(xbar, ybar)
  Covariance
(sum of above):
4.57 4.43     -25.71

 

Discussion

There is no limit to covariance, which makes it difficult to assess given a single calculation. It has more value when several sets of similar figures have their covariances calculated. In this case, the set with the highest figure has the greatest matching.

SPSS: Analyze, Correlate, Bivariate; Options: Cross-product deviations and covariations.

See also

 

Site Menu

| Home | Top | Quick Links | Settings |

Main sections: | Disciplines | Techniques | Principles | Explanations | Theories |

Other sections: | Blog! | Quotes | Guest articles | Analysis | Books | Help |

More pages: | Contact | Caveat | About | Students | Webmasters | Awards | Guestbook | Feedback | Sitemap | Changes |

Settings: | Computer layout | Mobile layout | Small font | Medium font | Large font | Translate |

 

You can buy books here

More Kindle books:

And the big
paperback book


Look inside

 

Please help and share:

 

Quick links

Disciplines

* Argument
* Brand management
* Change Management
* Coaching
* Communication
* Counseling
* Game Design
* Human Resources
* Job-finding
* Leadership
* Marketing
* Politics
* Propaganda
* Rhetoric
* Negotiation
* Psychoanalysis
* Sales
* Sociology
* Storytelling
* Teaching
* Warfare
* Workplace design

Techniques

* Assertiveness
* Body language
* Change techniques
* Closing techniques
* Conversation
* Confidence tricks
* Conversion
* Creative techniques
* General techniques
* Happiness
* Hypnotism
* Interrogation
* Language
* Listening
* Negotiation tactics
* Objection handling
* Propaganda
* Problem-solving
* Public speaking
* Questioning
* Using repetition
* Resisting persuasion
* Self-development
* Sequential requests
* Storytelling
* Stress Management
* Tipping
* Using humor
* Willpower

Principles

* Principles

Explanations

* Behaviors
* Beliefs
* Brain stuff
* Conditioning
* Coping Mechanisms
* Critical Theory
* Culture
* Decisions
* Emotions
* Evolution
* Gender
* Games
* Groups
* Habit
* Identity
* Learning
* Meaning
* Memory
* Motivation
* Models
* Needs
* Personality
* Power
* Preferences
* Research
* Relationships
* SIFT Model
* Social Research
* Stress
* Trust
* Values

Theories

* Alphabetic list
* Theory types

And

About
Guest Articles
Blog!
Books
Changes
Contact
Guestbook
Quotes
Students
Webmasters

 

| Home | Top | Menu | Quick Links |

© Changing Works 2002-
Massive Content — Maximum Speed

Site Menu

| Home | Top | Quick Links | Settings |

Main sections: | Disciplines | Techniques | Principles | Explanations | Theories |

Other sections: | Blog! | Quotes | Guest articles | Analysis | Books | Help |

More pages: | Contact | Caveat | About | Students | Webmasters | Awards | Guestbook | Feedback | Sitemap | Changes |

Settings: | Computer layout | Mobile layout | Small font | Medium font | Large font | Translate |

 

 

Please help and share:

 

Quick links

Disciplines

* Argument
* Brand management
* Change Management
* Coaching
* Communication
* Counseling
* Game Design
* Human Resources
* Job-finding
* Leadership
* Marketing
* Politics
* Propaganda
* Rhetoric
* Negotiation
* Psychoanalysis
* Sales
* Sociology
* Storytelling
* Teaching
* Warfare
* Workplace design

Techniques

* Assertiveness
* Body language
* Change techniques
* Closing techniques
* Conversation
* Confidence tricks
* Conversion
* Creative techniques
* General techniques
* Happiness
* Hypnotism
* Interrogation
* Language
* Listening
* Negotiation tactics
* Objection handling
* Propaganda
* Problem-solving
* Public speaking
* Questioning
* Using repetition
* Resisting persuasion
* Self-development
* Sequential requests
* Storytelling
* Stress Management
* Tipping
* Using humor
* Willpower

Principles

+ Principles

Explanations

* Behaviors
* Beliefs
* Brain stuff
* Conditioning
* Coping Mechanisms
* Critical Theory
* Culture
* Decisions
* Emotions
* Evolution
* Gender
* Games
* Groups
* Habit
* Identity
* Learning
* Meaning
* Memory
* Motivation
* Models
* Needs
* Personality
* Power
* Preferences
* Research
* Relationships
* SIFT Model
* Social Research
* Stress
* Trust
* Values

Theories

* Alphabetic list
* Theory types

And

About
Guest Articles
Blog!
Books
Changes
Contact
Guestbook
Quotes
Students
Webmasters

 

| Home | Top | Menu | Quick Links |

© Changing Works 2002-
Massive Content — Maximum Speed