Non-Experimental Methods Flashcards
What are examples of non-experimental methods?
Correlational studies
Single-variable studies
Case studies
What is a correlation?
An association / relationship between co-variables.
What do correlational studies measure?
The movement and direction of co-variables in response to each other.
What do correlational studies NOT measure?
The effect of an IV on the DV.
What are the types of correlation?
Positive correlation
Negative correlation
Zero correlation
What is a positive correlation?
As one variable increases the other variable increases.
What is a negative correlation?
As one variable increases the other variable decreases.
What is zero correlation?
No relationship between the variables.
Give examples of a positive, negative and zero correlation.
Positive =
Height and shoe size.
Negative =
GCSE grade and amount of time absent from school
Zero =
Amount of rainfall and number of people who read Harry Potter.
What is a correlation coefficient?
Used to measure the STRENGTH and NATURE (positive / negative) of the relationship between 2 co-variables.
What can the correlation coefficient number range between?
Between -1.0 and +1.0
The closer the number to +1 or -1, the stronger the correlation.
Weak correlation = x<0.5 or x>-0.5
Strong correlation = x>0.5 or x<-0.5
Perfect positive correlation = +1
Perfect negative correlation = -1
What graph shows a correlation between two co-variables?
Scattergram
or
Scattergraph
What are the strengths of correlational techniques?
= Provides valuable insight =
Correlations - measure strength of relationship - valuable insight for future research to be conducted.
= Ethics =
Can be used when a lab experiment would be unethical as the variables aren’t manipulated, only correlated.
What are the weaknesses of correlational techniques?
= Cause & Effect =
Not possible to establish cause & effect relationship - other factors may have influenced relationship - aka third variable problems.
= Linear & Curvilinear =
Correlations only identify linear relationships, not curvilinear.
E.G. relationship between temp and aggression is curvilinear.
