Week 3 Notes
What is a theory?
General principle
Organizes facts systematically
Guides scientific research
Experimental Method:
Variables:
Independant: IV
IV treatment manipulated to determine if causing change in behaviour or condition.
Dependant: DV
Measured at the end of experiment.
Varies as IV is manipulated.
Experiment Group - exposed to IV
Control group - exposed to same experimental environment but not given IV
treatment.
Rule out chance - controlled lab setting
Generalized findings - researchers must replicate/repeat experiment.
Use different people.
Problems in Experimental Research:
Selection bias: systematic differences among groups present at beginning of
experiment.
Difference at end of experiment may be due to pre-existing differences in groups.
Use random assignment to help i.e. assignment of participants to experimental &
control groups through chance procedure - guarantees participants have equal
probability of being placed in any group.
Placebo effect: improvement from power of suggestion.
Placebo - sugar pill or injection of saline solution.
Use control group to test whether results due to treatment or placebo effect.
Experimenter bias: preconceived expectations cause them to find what they expect to
find.
What is a theory?
General principle
Organizes facts systematically
Guides scientific research
Experimental Method:
Variables:
Independant: IV
IV treatment manipulated to determine if causing change in behaviour or condition.
Dependant: DV
Measured at the end of experiment.
Varies as IV is manipulated.
Experiment Group - exposed to IV
Control group - exposed to same experimental environment but not given IV
treatment.
Rule out chance - controlled lab setting
Generalized findings - researchers must replicate/repeat experiment.
Use different people.
Problems in Experimental Research:
Selection bias: systematic differences among groups present at beginning of
experiment.
Difference at end of experiment may be due to pre-existing differences in groups.
Use random assignment to help i.e. assignment of participants to experimental &
control groups through chance procedure - guarantees participants have equal
probability of being placed in any group.
Placebo effect: improvement from power of suggestion.
Placebo - sugar pill or injection of saline solution.
Use control group to test whether results due to treatment or placebo effect.
Experimenter bias: preconceived expectations cause them to find what they expect to
find.
