Study design Flashcards
Scientific method
Once a hypothesis is formulated it must be repeatedly tested by experimentation
4 things a theory must do to survive
- Consistent
- Predict results
- Explain future observations
- Re evaluate continually
Hierarchy of scientific evidence order
Stronger evidence nearer the top and weaker evidence lower the bottom
Observational study definition
Participants are naturally observed then compared against other observed groups
Why do we do observational studies
- Large samples
- Long duration of follow up
- Valuable
- Monitor effectiveness
Experimental study definition
Effect of intervention, in order to draw conclusions
Independent variable
What you change in the intervention/control group
Dependent variable
What you measure and so the outcome
Parallel experimental design
Participants are recruited and randomly allocated to 1 or 2 interventions
Crossover experimental design
All participants receive all conditions. Do one condition, have a washout period in between before completing the next condition
Randomised Control Trials (RCTs)
All participants of similar characteristics, then randomly assigned into 2 different groups (1) Placebo and (2) Intervention
Findings are less likely to be biased if you …
- Large sample
- Randomly selected sample
- Randomly allocate participants
- Blinding researcher/participants
- Control and measure everything
Single blinded
Participants or the researchers aren’t aware of the group allocation
Double blinded
Both the participants and the researchers aren’t aware of the group allocation which helps to prevent bias
Placebo groups
Groups who don’t receive any treatment to allow for comparisons
