Psychology Lecture 6 (chapter 2, Slide 1-16)
Slide 5: Correlational experiment helps you that there is a relationship between the shark and the cage,
but not exactly how.
Slide 7: Design experiment to answer question properly.
Eye colour is a variable –blue, black green etc., but even among a colour there are various spectrums
Value of a variable: the specific value that a variable can take. Ex. Age=variable. 20 years= value
In an experiment, you want to have the cause present, but in another trial you take it away, so that you
know that the cause is the actual cause of the event.
Independent Variable: related to cause
Dependent variable: related to effect. It depends on the value of the independent variable.
Ex: the shark and the cage- it seems the metal produces an electrical field that attracts the shark that is
so alien that they become aggressive towards the cage.
Test- condition where electrical field is present, and in another it’s not.
Independent- presence of electrical field
Dependent- sharks aggression; if the electrical field is present, it’s aggressive.
Control group- tries to measure/create a normal condition where the cause is not present (ie. The
electrical field is not present, and you observe the shark in its normal state)
Experimental group- where the e. field is present, and watch the shark behave.
Slide 9:A very specific experiment to test this hypothesis: operationally defined variables.
Ex: Students learn better if encouraged to participate. Not specific- what do you mean by encourage?
Participate? How do you design an experiment?
Control: class is not encouraged to participate: typical lecture
Experiment: class is actively involved: get participation marks, ask students, threaten if they fail to
participate, provide positive feedback, iclickers, upload powerpoint ahead of time for less note taking
Manipulation check- someone who doesn’t know which is which to observe how actively the students
But how do we know if they learned anything? Assessment devices (tests, assignments etc). But operational devices are difficult to assess because others can openly look at it and ask- how did you
Worry that operational devices are not effective
Slide 12: validity- how well the definitions capture the experiment (ex. Manipulation checks- the
observer does not know which one is the experimental class, but assess classroom involvement)
Converging evidence- someone testing th