Inhoudsopgave
Week 1.......................................................................................................................................................... 1
Week 2.......................................................................................................................................................... 5
Week 3.......................................................................................................................................................... 9
Week 4........................................................................................................................................................ 13
Week 1
What is a theory?
A theory is a set of statements that describe established relationships, supported by previous
research. It can be represented by a model.
A theory consists of assumptions, variables (either conceptual or operationalized) and
propositions about the relationships between these variables.
A hypothesis is the relationship between operationalized variables that is expected by the
researcher, if the theory is correct. A good hypothesis makes clear how the study will be
conducted (operationalisation of the variables).
Preregistration involves writing down your hypothesis, analysis and experimental design
before conducting the study. This avoids:
Hypothesizing After The Results Are Known. Especially hypotheses should always be
stated beforehand. In a dataset, the chances are high that two variables will correlate,
even if the constructs are not really correlated.
P-hacking (many ways of analyzing the data are tried: result is likely to be a
coincidence)
Publication bias (findings not supporting the hypothesis may not be published)
After preregistration, the amount of studies showing an effect drastically decreased (Kaplan
& Irvin, 2015).
The independent variables in a theory must be uncorrelated, independent and orthogonal
(all three of these things mean that there may not be a relationship between the
independent/explanatory variables).
Mediating variables help explain the relationship. It is often analyzed by multiple regression.
The influence of A on B will be measured with and without predictor C. If C is a
mediatior, there will be no effect without it.
A moderating variable changes the relationship. It can be measured by multiple regression if
the moderator is categorical (interaction). It can also be measured by ANOVA.
, One subgroup with low predictor C, one subgroup with high predictor C. If C is a
moderator, A will have a larger effect on B when C is high.
The theory-data cycle
Theory
Research questions
Supportive: Research design Not
support of supportive:
data revision of
theory
Ideally: pre-registered
hypothesis
Data
What makes a good theory?
A good theory is:
- Logically consistent
- Falsifiable
- In agreement with the data
- Clear and specific
- Parsimonious (the simplest explanation of the phenomenon)
- Consistent with other theories
- Useful/predictive
Merton’s scientific norms
1. Universalism. The evaluation of scientific claims must be independent of the
researcher’s credentials or reputation.
2. Communality. Scientific knowledge is created and belongs to the community.
3. Disinterestedness. Scientists must strive to discover the truth and must be neutral.
Week 1.......................................................................................................................................................... 1
Week 2.......................................................................................................................................................... 5
Week 3.......................................................................................................................................................... 9
Week 4........................................................................................................................................................ 13
Week 1
What is a theory?
A theory is a set of statements that describe established relationships, supported by previous
research. It can be represented by a model.
A theory consists of assumptions, variables (either conceptual or operationalized) and
propositions about the relationships between these variables.
A hypothesis is the relationship between operationalized variables that is expected by the
researcher, if the theory is correct. A good hypothesis makes clear how the study will be
conducted (operationalisation of the variables).
Preregistration involves writing down your hypothesis, analysis and experimental design
before conducting the study. This avoids:
Hypothesizing After The Results Are Known. Especially hypotheses should always be
stated beforehand. In a dataset, the chances are high that two variables will correlate,
even if the constructs are not really correlated.
P-hacking (many ways of analyzing the data are tried: result is likely to be a
coincidence)
Publication bias (findings not supporting the hypothesis may not be published)
After preregistration, the amount of studies showing an effect drastically decreased (Kaplan
& Irvin, 2015).
The independent variables in a theory must be uncorrelated, independent and orthogonal
(all three of these things mean that there may not be a relationship between the
independent/explanatory variables).
Mediating variables help explain the relationship. It is often analyzed by multiple regression.
The influence of A on B will be measured with and without predictor C. If C is a
mediatior, there will be no effect without it.
A moderating variable changes the relationship. It can be measured by multiple regression if
the moderator is categorical (interaction). It can also be measured by ANOVA.
, One subgroup with low predictor C, one subgroup with high predictor C. If C is a
moderator, A will have a larger effect on B when C is high.
The theory-data cycle
Theory
Research questions
Supportive: Research design Not
support of supportive:
data revision of
theory
Ideally: pre-registered
hypothesis
Data
What makes a good theory?
A good theory is:
- Logically consistent
- Falsifiable
- In agreement with the data
- Clear and specific
- Parsimonious (the simplest explanation of the phenomenon)
- Consistent with other theories
- Useful/predictive
Merton’s scientific norms
1. Universalism. The evaluation of scientific claims must be independent of the
researcher’s credentials or reputation.
2. Communality. Scientific knowledge is created and belongs to the community.
3. Disinterestedness. Scientists must strive to discover the truth and must be neutral.
