33. EXTERNAL VALIDITY Flashcards
1
Q
- What is the key to External Validity?
A
- good sampling
THE SAMPLE:
- should be representative of the wider population of
interest
- the sample should be large enough to give adequate
statistical power
2
Q
- What is our interest when it comes to External Validity?
A
WHETHER THE FINDINGS CAN BE GENERALISED:
- to the general population
- to other similar populations
3
Q
- Look at this example.
What questions would we ask with regards to the External Validity?
A
- Do the results apply to the general Population of
Cyprus? - Do the results apply for University students in other
countries?
4
Q
- How do we determine if the results of the study have a low external Validity?
A
- THE RESEARCHER
- must make the correct judgement
- WHETHER THE STUDY SAMPLE IS REPRESENTATIVE
- of the whole population
- or similar populations in other countries
5
Q
- What is helpful for evaluating the External Validity of the findings?
A
- going through the literature
- investigating the evidence on the association of
interest
6
Q
- Should we assume that our findings are Externally Valid?
A
- NEVER
- unless we have carefully thought it through
- and investigated it
7
Q
- How do we improve the Validity of our Sample?
A
- WE SHOULD AVOID HIGHLY SELECTED SAMPLES
- this helps to generalise the results to the general
population
- choosing a Random sample is the best approach - THE SAMPLE HAS TO ACCURATELY REPRESENT THE
SPECIFIC POPULATION SUB-GROUP
- when we have intentionally chosen a population with
specific characteristics
8
Q
- What must we do when we have a sample that only consists of a population with specific characteristics?
A
- we cannot generalise this information to the general
public - generalisations to other populations can be done
- if the populations are similar
- if there are certain assumptions made
9
Q
- In this study, in which cases is this sample representative?
A
- THIS IS NOT A REPRESENTATIVE SAMPLE
- of the general population
- since it consists only of male US Health Professionals - IT COULD BE A REPRESENTATIVE SAMPLE
- of health professional in other similar counties
10
Q
- In this study, what can be said about the External Validity?
A
- THE EXTERNAL VALIDITY IS LOW
- in terms of generalising the findings to the General
Population - THE EXTERNAL VALIDITY COULD BE ADEQUATE
- in terms of generalising to the Health professionals in
other first world countries that are similar to the US
NB:
- since we are dealing with a biological effect
- we could be more flexible when generalising it to the
general population
11
Q
- Will we use these results when dealing with the general population?
A
- the study should be explored more
- the study can be redone by using a Random sample
12
Q
- Other than Chance, what can be said about the ay in which we analyse the Internal and the External Validity of a study?
A
- it is subjective in nature
IT REQUIRES:
- experience
- critical thinking
- informed judgement from the researcher
