Dealing with bias and uncertainty Flashcards
What is the purpose of research?
aim is to develop new treatments and information to benefit people
What are the types of research methods?
Quantitative: Measure numerical data in small group of people; specific
study design, analyse, generalise findings to population.
Qualitative: Understanding underlying reasons, opinions, & motivations;
non-numerical data.
What is the difference between observational and experimental study design?
Observational Designs:
- No intervention.
- Record behaviours, attitudes & symptoms - Naturalistic:
- Investigating associations
- Example: Cohort studies; Cross-sectional studies (inc. surveys).
Experimental Designs: (Factorial Designs)
- Researcher controls or introduces factor
- Effectiveness of new antidepressant drug.
- Record effects of intervention on outcomes:
- Investigate sources variability.
What is a prospective cohort study?
What are the different types of bias?
Selection Bias: Systematic difference between population & sample
Non-response Bias: Systematic difference between non-responders & responders (survey)
Volunteer Bias: Systematic difference between volunteers & population
Response Bias: Systematic difference between participant response & “truth”
Assessor Bias: Systematic difference between assessor measurement of
participant & “truth”
What are the different methods of sampling?
Simple random sampling
- sampling frame for population
- every member has equal probability of selection
- representative sample
Convenience sampling
- particiapnts convenient to access eg. single hospital
A control group is essential in research
How can bias be reduced?
Difficult to remove, only minimise biases (generally).
❖ Experimental Designs: Aspects of methodological designs.
❖ Observational Designs: Harder to control.
Hawthorne Effect: Change in participants’ behavior due to attention received in study.
What can a hypothesis tell us?
Initates the research - usually based on anecdotal evidence
