PSY240 - Lecture 3
Components of a Research Study
x There is misrepresentation in the media of research findings. The science that
Problems associated with researching abnormal psychology
x Thoughts and feelings are hard to measure because it is highly subjective and the
person feeling it has to be able to communicate it. People might not be aware of these
internal states. Emotional states might not be quantifiable.
x People change. It is hard to categorize behaviour that is changing frequently. One
person can be depressed one day and not the next
x Abnormality has multiple causes, we need researchers who look at a problem from all
aspects, not just one perspective. We are left with a small portion of the puzzle at one
x Hard to manipulate variables. How do you manipulate stress, if you are trying to
show that stress leads to depression
scientific approach that requires ideas to be stated in a clear precise way. It is an
educated guess that could be supported or reputed by tested. E.g. test stress causes
depression. Loss of love one, no loss of love run. Stressful exam before exam taking
MCats. Do certain stressors cause certain symptoms of depression? More specific
The null hypothesis is the alternative of the hypothesis, stress and depression are
To determine if it is statistically significant 5%, we need to now the sample size.
Statistics have to be run.
b. Independent and Dependent Variables
x Dependent variable is a variable is the phenomenon that we are examining that we
think is going to change with the introduction of a factor. E.g. level of depression.
x The independent variable is the one that is manipulated, the factor that is to see if it
gives change to the dependent variable. E.g. treatment groups.
x CONSISTENCY. Is the research findings can be reproduced over time.
Internal and External Validity
x Validity can result in b/c of the change in the IV instead of some other factor.
x Internal validity
o Dealing with confounding variables. (psych treatment vs. medicine treatment:
confounds: placebo effect, more severely depressed choose the medicine
treatment, inherent bias in the sample)
o Confound any factor in the study that makes the result inexplicable.
The control group: people come into a study are assigned to be either
in an experimental group exposed to the IV and the other will not be.
Helps rule out alternative findings. Best thing to get placebo effect- in
the medication treatment of depression anxiety is very strong.
Randomization: process of assigning people to different research
groups, equal probability of being placed in either group. Eliminates