Research Methodology
Notes on the lectures and the book
Tilburg University
2017-2018
,Introduction to research psychology
Lecture 1
Exam material:
Everything in the lectures
The entire book (except for chapter 9)
Test:
30 MC questions & 1 essay (1 sentence) question
Each practical has 3 test questions
Lowest score of the test will be removed, the other 9 will be 1/3 of your fnal grade if it’s higher than
the exam grade.
Sources of knowledge (that aren’t knowledge)
- Intuition: a gut feeling. Plays an important role in gaining knowledge, but it’s not knowledge itself.
Cognitive bias:
- People ofen get convinced stories are true when they are not.
- What comes to mind easily, recent or memorable events, tend to bias our thinking (=
availability heuristic).
- We ofen only look for what happened, but not what didn’t happen (= present/present
bias). For 2 subjects the medicine has worked, but we forget that it doesn’t work for 10
others.
Motivational bias:
- We focus on the outcome we like best
- We ask biased questions to get the expected answers/results (= confrmatory hypothesis
testing)
- We ofen don’t know that we’re biased (= bias blind spot)
- Personal experience: your own experience. Also important to generate new ideas, but isn’t
legitimate evidence
Sampling bias: when your observations are probably not representative for the population.
The one observation you have isn’t representative for all the other times it didn’t happen
(comparison groups). When someone calls you the moment you called her, doesn’t mean
she called you the other 99 times you should of her.
Observer bias: when your observations are infuenced by your expectations. Afer I went to
the therapist I feel beterr, because you were expecting to.
Confounding: when the factor of interest systematically varies with other factors that could
also have an efect. If could just be that you got beter by yourself or went outside etc.
Personal experiences are too messy to draw conclusions
- Common sense: everyone knows … Ofen turns out to be wrong, it isn’t knowledge
Woman can’t go to universityr
The earth is fatr
- Authority: it’s true because an authority fgure says so. You can’t just appeal to authority, you need
, references and facts
Some authorities are more reliable than others
The scientiic method
- Be prepared to test your ideas against observations
- Respect those observations, even if they don’t match your original idea
Scientic publicatons oork because:
- Open methodology (explain openly how you performed your research)
- Connection evidence & conclusion is public
- Other researchers can dispute conclusions and redo the research
Science is self-correcting because of the points above.
The empirical cycle
Observation → Theory → Prediction → Testing → Evaluating → Observation → repeat
1. Observation: Diferent groups of people speak diferent languages
2. Theory: What is the original language? Egyptian of course!r
3. Prediction: If Egyptian is the natural language, a baby that has never been in contact with
humans If…., then….r
4. Testing: Locked up a baby and monitored that its babbling. The baby saw a piece of bread
and started speaking French.
5. Evaluation: The babbling was interpreted as evidence against the theory. They concluded
that the original language must be French, so he evaluated his theory.
Irrefutable theories
- Some theories cannot be tested, they’re worthless
- Religious theories: there’s nothing that can happen that won’t have to do with God, so God isn’t
scientifc, it can’t be tested.
Irrefutable statements aren’t falsiiable
- The brain is controlled by litle green men that can hide when you try to fnd them.r This theory is
worthless because you can’t falsify it.
The empirical cycle is typical for science. However, it doesn’t guarantee scientifcally proven factsr.
Scientifc research shows Xr isn’t the same as X is truer.
Correction mechanisms
Science doesn’t have a boss who decides what is good or bad science, there are only 2 correction
mechanisms (so some publications can contain nonsense)
Replication: performing the empirical cycle repeatedly to prove something.
Researchers rarely trust a single study, it needs to be replicated by diferent researchers,
locations and methods. If there is a certain amount of this it will become a fact.
, Peer review: Afer publication, reviewers are correcting and checking your paper. It’s the
barrier between you and publication. They are picked by the editor and peers. It’s the best
thing we have, but sometimes the peer reviewers are slacking and it isn’t corrected well.
Researcher -> editor -> reviewers
Science is self-correcting
Falsiiability: If theory X wasn’t true, then...r,