A correlation means that there is a relationship between two or more variables.
This does not imply, however, that there is necessarily a cause or effect relationship between them.
A correlation coefficient is a number that expresses the strength of the relationship between the two variables.
Correlations indicate relationships between variables.Kiatdd / Wikimedia Commons
It is important to remember that while correlations can help show a relationship, correlation does not indicate causation.
What Is a Correlation Coefficient?
Instead of performing anexperiment, researchers may collect data to look at possible relationships between variables.
Scatter Plot diagram.Investopedia
The closer it is to +/-1, the stronger it is.
Types of Correlation
Correlation strength ranges from -1 to +1.
In other words, +1 is the strong positive correlation you’re able to find.
A zero correlation is often indicated using the abbreviationr= 0.
The horizontal axis represents one variable, and the vertical axis represents the other.
Investopedia
Each point on the plot is a different measurement.
From those measurements, a trend line can be calculated.
The correlation coefficient is the slope of that line.
When the correlation is weak (ris close to zero), the line is hard to distinguish.
When the correlation is strong (ris close to 1), the line will be more apparent.
A correlation of +0.10 is weaker than -0.74, and a correlation of -0.98 is stronger than +0.79.
Correlation Does Not Equal Causation
Correlation does not equal causation.
Just because two variables have a relationship does not mean that changes in one variablecausechanges in the other.
An oft-cited example is the correlation between ice cream consumption and homicide rates.
Studies have found a correlation between increased ice cream sales and spikes in homicides.
However, eating ice cream does not cause you to commit murder.
Instead, there is a third variable: heat.
Both variables increaseduring summertime.
These illusory correlations can occur both in scientific investigations and in real-world situations.
Stereotypesare a good example of illusory correlations.
For example, suppose someone holds the mistaken belief that all people from small towns are extremely kind.
Confusing correlation with causation assumes a cause-effect relationship that might not exist.
Correlations range from -1.00 to +1.00.
The correlation coefficient (expressed asr) shows the direction and strength of a relationship between two variables.
The closer thervalue is to +1 or -1, the stronger the linear relationship between the two variables is.
Correlations indicate a relationship between two variables, but one doesn’t necessarily cause the other to change.
Mukaka M.A guide to appropriate use of correlation coefficient in medical research.Malawi Med J.
2012;24(3):69-71.
Heath W.Psychology Research Methods: Connecting Research to Students Lives.
Association for Psychological Science.Research states that prejudice comes from a basic human need and way of thinking.
In: Swinscow TDV.Statistics at Square One.
