What is scientific inquiry?
• Bias: prejudice that may lead to some sort of error because the data are skewed.
The scientific method depends on theories, hypotheses, and research
• Theory – an example of a theory is the theory of evolution and natural selection,
selection of favourable traits of a species that helps them adapt better to the
If everything you hypothesized was true, you might want to move on to a next theory or
refine it, if your hypothesis is bad, then you have to look at a whole new theory. The
research is never finished, there’s always something to be done and researched.
Research leads to more research.
HOMER: hypothesize, operationalize, measure, evaluate, and revise/report
Difference between hypothesis and theory:
Theory is something that’s vague, has multiple variables and general. And ideally
both theory and hypothesis are true. The hypothesis is a more specific statement
and is the one being tested.
Theory hypothesis, making big step in operationalization
Testing driving ability: driving simulation, but would that test directly the theory
that drinking alcohol impairs driving ability. Driving simulator is only a part of
what you experience in actual driving and that affects your hypothesis. Your
hypothesis would have to be drinking alcohol impairs your ability to drive in a
In a driving simulation test you can test reaction time, speed, and the number of
Test coordination and motor control by testing subjects on a closed course.
Coordination and motor control by tests other than driving (like the police tests of
having to walk in a straight line, touching your nose with your eyes closed, alphabet
Theories should generate hypotheses.
Good theory produces a lot of good testable hypotheses.
Freud was very influential, but his theories were much more vague and less
testable. Dream theory: when you dream about something, is a way of your
subconscious of getting what it can’t get in reality. But this theory isn’t exactly very
Unexpected findings can be valuable.
Serendipity: by chance
Research findings of cats responding differently to growing up in vertical lines and
then being exposed to horizontal lines and not having any balance are an example of chance findings that are unexpected. Unexpected findings are the most well-
known and create new paradimes that no one was aware of before.
Variable: is measurable; can and should take many values between the subjects of your
study. Has to create variance between your subjects; quantification (can give a
number to the measurement); qualification (description).
Maybe certain areas in psychology where quantification may fall short
Developmental designs are important.
Longitudinal designs: following sample/subjects and repeatedly assess them over
Cross-sectional: one time assessment of subjects at one time point only and try to
analyze data from there
An observer bias:
Observer is making a systematic mistake in the behaviour he/she is observing.
Intentional and unintentional bias; Can change the results; reporting violence in a
culture that is in fact just performing a ritual and this bias is caused by your
background and ignorance about that culture.
Cohort effect: unidentified variables may be involved – assume you are interested in
finding out how a certain motor ability of subjects changes with age, recruit subjects that
are of 20, 30, 40, 50, 60, 70, 80 years old and you have 50 subjects in each sample. And
you see that the people above 50 have poorer motor skills. Prone to cohort effect – where if
a war happened the people happened to be in and affect their skills. Also, eyesight
decreases with age, and maybe the test involves vision. People over 50 didn’t necessarily
have technology. People over 50 more exposed to more gross motor work and not fine
motor work. Older people have not had access to computers, and video games which gives
rise to really fine motor skills and gives you a lot of motor training as opposed to people
who did not grow up with those technologies.
Expectancy bias experiment with the rats: conclusion that the students gave off subtle cues
that affected the rat’s behaviour. A subtle cue can include impatience, or aggression, spatial
cues, verbal (emotionally friendly or unfriendly tone).
Clever Hans: the horse that “could do math”; the trainer wasn’t the one affecting the
horse’s behaviour. Because the horse can’t do math. The person giving the horse the
question was reacting and the horse could read the person’s reaction and the horse would
know when to stop. The solution is to give a question to someone who doesn’t know the
answer, so that the person can’t give off cues and the horse is completely on his own and
the horse got the wrong answers. This is a powerful example of the observer bias.
Idea that water would retain the molecular structure of even the most diluted of solutions Research comments: dilution was so great, was the same that you can throw car keys in a
river and then take the water from the river and still start the car.
When to believe the unbelievable. Nature themselves found out that it was a hoax because
one of the experimenters already knew the outcome of the experiment and that was enough
to skew the data and show that the water has the memory of the molecule dissolved in it.
Safeguards against biases
Placebo-controlled studies – give something to the group that doesn’t have any
active ingredients that can affect the subjects to see how much of the effect is due to
expectation within the experiment (experiment expectancy).
Can only trick your body for so long before, say, your neurons succumb to the
disease. If your product is just as effective as the placebo, then it’s not good enough
to be placed on the market. Your product has to have better effects than the placebo
– want something that has placebo plus an added value.
Randomized study – randomly select from the population, however this is often not
accomplished, we get a convenient sample where the people “selected” are really,
in fact, volunteers, and they participate because they are motivated by incentives
given by the people conducting the research (like monetary rewards). Psychological
studies happen with psychology students in the university and are really volunteers.
Not based on population samples, but on individuals.
(Double) blind studies – A study is blind when the subject doesn’t know whether
they are in the active or the control group.
Double blind study is when the experimenter doesn’t even know whether the pill
they are giving are the control or the placebo. Bring in a third person who is not
evaluating the results.
Cross-over study – if you have the pill example, then after a given time, you would
switch what you’re giving your subjects from the active ingredient to the placebo to
see whether it actually works.
Correlational studies examine how variable are related.
Don’t have any intervention on the part of the observer – naturally-causing
You can’t know the cause of the problem though.
Sleep and stress are correlated but you don’t know which causes which.
Self-esteem and doing well in school
Eating ice cream and murder
What is wrong with everything is that they’re all correlated but what causes
the murder (summer heat – it’s a third variable, under summer heat, people
tend to be more violent)
Ethical reasons for using correlational designs Making predictions
Independent and dependent variables *
Test whether nicotine affects he verbal aspect of the IQ test.
Able to control the consumption of nicotine
Take an IQ test; you have performance in terms of generation/reaction time
etc…and you see whether the results are different.
Independent variable: nicotine
Dependent variable: effect of nicotine on the verbal portion of the IQ test – reaction
Lying is stressful and when you tell a lie, your sympathetic nervous syst