01_Introduction Flashcards
What categories are used to evaluate the quality of empirical research?
- Objectivity
- Reliability
- Validity
What is Objectivity?
The measurements and results of the analysis are independent from researcher
–>Same result, if conducted by someone else
What is reliability?
= Absence of measurement errors
–>possible to reproduce results under constant condition
E(e) = 0
Reliability: how to improve reliability and what are ppotential causes of error?
- repeated measuring improves accurarcy (potentially)
Potential causes of error:
- lack of features consistency
- precision of measure
What is validity?
A measures measures what it is suppose to measure
Expected systematic error: E(s)= 0
Can repeated measuring improve results if validity is not given?
No:
because if validity is not given, that repeated measuring does not improve results
Is reliability a sufficient condition for validity?
No:
Reliability is a necessary,, but not sufficient condition for validity
Different forms of validity?
- Validity of statsitical interference:
- Internal validity
- Construct validity
- External validity
What is validity of statistical interference? (example)
Validity of statsitical interference: about the correlation (covariance) between treatment and outcome
—> the degree to which inferences and conclusions are meaningful and accurate
Example: if group sizes between control and treatment group differ ->low validity of statistical interfences
What is internal validity?
Internal validity: The validity of inferences about whether observed covariation between A (treatment) and B (outcome) reflects a causal relationship from A to B as thos variables were manipulated or measured
Ex: Is the intro of sales traning really the reason for increase in customer satisfaction?
What is Construct validity?
Construct validity: THe validity of inferences about the higher order consturcts that represent sampling particulars
Ex: Assesses the extent to which a measure or test truly represents the underlying theoretical construct or concept it is intended to measure
What is external validity?
External validity: the validity of inferences about whether the cause-effect relationship holds over variation in persons, settings, treatment variables, and measurement variables
Ex: extent to which the results are generalizable for other circumstances outside the study
Under which assumptions can a Causal relation be inferred?
Key element: A change in one variable causes a change in another varible
“If X is a cause of Y, we have in mind that a change in X produces a change in Y and not merely that a change in X is followed by or associated with a change in Y.”
Explanation of variables according ot their causal function?
(Independent, dependent, mediator, moderator)
independent variable: causes (x1,x2) (sales training)
dependent variable: efffect (CS)
Mediator: variable z by means of which x influences y –>explains the relationship
Moderator: variable m that effects the strength and direction between x and y –>influences the strength between a relationship (high, low moderator)
What is mediation?
Mediation openening the black box and explain the relationship
