Pagina 1 van 42
Quantitative research summary
Lecture 1 (in class lecture)
Quality criteria quantitative research
Internal validity The extent of certainty about the causal relationship
Important:
- eliminating confounding variable
- Cause should precede the e ect
External validity Can we generalize the results? Does it apply to
other similar cases?
Reproducability/ replicability Can we reproduce the study? Is it transparent what
the researcher did?
Hypothesis qualitative research
Testing hypothesis about the possible relationship between two or more variables is often a key
part of quantitative research.
Quantitative research has often research question where 2 or more answers are possible. In
hypothesis testing, these answers are identi ed béfore the data collection.
You can have:
NULL HYPOTHESIS You predict that the independent variable will have
no e ect on the dependent variable.
ALTERNATIVE HYPOTEHSIS You predicts the independent variable will have a
demonstrable e ect on the dependent variable.
The research will enable you to test the question of e ect or no e ect and show if the hypothesis
is true or false.
Positive and negative relationship between variables
Postitive relation If one increases the other increases as well
Negative relation If one increases the other one decreases
Moderator an in uence or variable that a ects the relationship
between two or more factors or variables.
a moderating variable (or moderator) a ects the
strength and direction of the relationship between 2
variables.
example of this
- gender is the moderator (Factor/variable) it in uences the other 2 variables.
- Positive relation & negative relation
fffl ff ffff ff fi fl ff ff
, Pagina 2 van 42
The expectation of positive or negative relation are about the direction of the relationship, not
about the starting point or the size of the di erence! So could be both:
Mediating vs confounding variable
Mediating variable A mediating variable (or mediator) explains the
process through which two variables are related.
(It basically explains cause and e ect, see image
below)
Confounding variable Alternative explanation (those that a ect other
variables in a way that produces spurious or
distorted associations between two variables)
di erence mediator vs moderator:
A mediating variable (or mediator) explains the process through which two variables are related,
while a moderating variable (or moderator) a ects the strength and direction of that relationship
Example mediating:
Implicit gender Work-family
Job satisfaction
stereotypes guilt
Mediator variable Dependent variable
Independent variable
ff
ff ff ffff
Quantitative research summary
Lecture 1 (in class lecture)
Quality criteria quantitative research
Internal validity The extent of certainty about the causal relationship
Important:
- eliminating confounding variable
- Cause should precede the e ect
External validity Can we generalize the results? Does it apply to
other similar cases?
Reproducability/ replicability Can we reproduce the study? Is it transparent what
the researcher did?
Hypothesis qualitative research
Testing hypothesis about the possible relationship between two or more variables is often a key
part of quantitative research.
Quantitative research has often research question where 2 or more answers are possible. In
hypothesis testing, these answers are identi ed béfore the data collection.
You can have:
NULL HYPOTHESIS You predict that the independent variable will have
no e ect on the dependent variable.
ALTERNATIVE HYPOTEHSIS You predicts the independent variable will have a
demonstrable e ect on the dependent variable.
The research will enable you to test the question of e ect or no e ect and show if the hypothesis
is true or false.
Positive and negative relationship between variables
Postitive relation If one increases the other increases as well
Negative relation If one increases the other one decreases
Moderator an in uence or variable that a ects the relationship
between two or more factors or variables.
a moderating variable (or moderator) a ects the
strength and direction of the relationship between 2
variables.
example of this
- gender is the moderator (Factor/variable) it in uences the other 2 variables.
- Positive relation & negative relation
fffl ff ffff ff fi fl ff ff
, Pagina 2 van 42
The expectation of positive or negative relation are about the direction of the relationship, not
about the starting point or the size of the di erence! So could be both:
Mediating vs confounding variable
Mediating variable A mediating variable (or mediator) explains the
process through which two variables are related.
(It basically explains cause and e ect, see image
below)
Confounding variable Alternative explanation (those that a ect other
variables in a way that produces spurious or
distorted associations between two variables)
di erence mediator vs moderator:
A mediating variable (or mediator) explains the process through which two variables are related,
while a moderating variable (or moderator) a ects the strength and direction of that relationship
Example mediating:
Implicit gender Work-family
Job satisfaction
stereotypes guilt
Mediator variable Dependent variable
Independent variable
ff
ff ff ffff
