Research Methods and Techniques II: Quantitative Methods
Les 1:
Introduction to scientific reasoning
Overview lecture:
1. Psychology is a way of thinking (chapter 1)
2. Sources of information (chapter 2)
Chapter 1: psychology is a way of thinking
Everything psychologists learn is knowledge acquired through scientific research.
Producing versus consuming research:
Slide 4: research producer / research consumer →how to help patients, which treatment to use? You
need to be able to read and understand studies
Example to illustrate the importance of the research consumer role (slide 5):
o Griet works as a therapist but doesn’t have a degree in psychology, she claims she doesn’t
need it because she has studied other things
o she referred to a study that a type of therapy works, but if you look closely you can see that
the study isn’t good: only 10-20 dns, no control group
Study shows that you can predict the future, with experimental evidence
o The study looks good: list of words, memorize, tell which words you remember, selected
words random that people had to write down →the words that were selected were the same
words the people remembered = predicted the future
o did a lot of studies but didn’t report all of them, analyze the data but changed it
o unable to replicate, triggered replication crisis
o Critical mindset is essential
o Not all published research is correct or robust
o Replication crisis in psychology: you cannot replicate a lot of psychological studies
The benefits of being a good consumer:
Example 1:
The "Scared Straight" program, aimed at deterring at-risk youth from crime by exposing them to the
harsh realities of prison life, may seem like a logical intervention. However, research has shown that
the program is not only ineffective but may actually increase criminal behavior among participants.
Several studies, including randomized controlled trials, found that those who attended Scared
Straight programs committed more crimes than those who did not. In some cases, crime rates among
participants increased by up to 20%. Due to these findings, the U.S. Department of Justice warns
against such programs, and the Juvenile Justice and Delinquency Prevention Act of 1974 was
amended to prohibit youth offenders from interacting with adult inmates in jails and prisons. This
,example underscores the importance of relying on empirical evidence rather than intuition when
evaluating intervention programs.
Example 2:
Michael Mrazek and his colleagues (2013) conducted a study to investigate the effects of mindfulness
on test performance. Participants were randomly assigned to either a 2-week mindfulness training
course or a 2-week nutrition course. At the end of the training, those who practiced mindfulness
showed less mind-wandering and improved their GRE scores compared to their previous
performance. In contrast, the nutrition course participants did not show these improvements.
This study suggests that mindfulness—focusing on the present moment without judgment—can
enhance concentration and academic performance. The findings support the idea that mindfulness
could be a useful tool for students looking to improve their study skills and test results.
How scientists work:
o Science is based on empiricism
o Scientists test theories
o Scientists work on fundamental and applied problems
o Science is continuously evolving
o Scientists publish their findings in scientific journals
o Scientists communicate with the general public via journalists
Empiricism:
o Empirical method is based on data obtained through:
➢ Our senses (sight, hearing, touch)
➢ Instruments that assist our senses (thermometer, questionnaires, timer)
o Empiricists aim to do research in a systematic (same way with all dns), rigorous (transparent
about how to collect data, others can be critical), and replicable (repeat) manner
o Empiricism is not based on own experiences, intuition, or authority figures
Scientists test theories: the theory-data cycle (p13):
1. Theory Formation – A theory is a set of general
principles explaining relationships between variables.
2. Research Questions & Hypotheses – The theory
guides researchers in forming specific research questions
and testable hypotheses.
3. Study Design & Data Collection – Researchers design
studies and collect data to test their hypotheses.
4. Data Analysis & Interpretation – If the data support
the hypothesis, confidence in the theory increases. If the
data contradict it, the theory is revised, or the research
design is improved.
5. Preregistration – To ensure transparency, researchers
ideally state their expected outcomes before collecting
data.
This process is cyclical, meaning theories are continuously tested, refined, or adjusted based on
new evidence
,Note:
There is a difference between exploratory (inductive) and confirmatory (deductive) research!
Confirmatory (deductive): Most start with theory and test this with hypothesis, is data in line with
hypothesis or not, change theory or study
Exploratory (inductive): learn how people think
Harlow (1958) (slide 10): Cupboard theory (attachment to the person who is feeding you) vs. Contact
comfort theory (attachment to the person gives you love, comfort) : study baby monkeys with 2
cages (bottle milk and hard or soft, warm figure and no food →monkeys go to the comfort cage
→study: 2 theories, hypothesis, data collection, conclusion
Scientists test theories:
o Characteristics of good theories
➢ Supported by data
➢ Falsifiable
➢ Parsimonious (“Occam’s razor”) (zuinig)
o Examples of non-falsifiable theories: (non-falsifiable = pseudoscience)
➢ Facilitated communication threatment believers (it will only work if you believe in it
→cant falsify )
➢ See book “De ongelovige Thomas heeft een punt”
o Theories are evaluated based on all available evidence
➢ A theory can never be “proven”, but it can be falsified (single confirming finding
cannot prove a theory, single disconfirming finding does not lead researchers to scrap
a theory. If hypothesis isn’t supported, they might say that data are inconsistent with
a theory. Scientists may troubleshoot the study instead of rejecting the theory.)
➢ Replication is crucial
➢ The simplest theory is the one that we will choose if we have more than one
Example pseudoscience: Facilitated Communication (FC) is technique where therapists guide dns with
developmental disorders to communicate via keyboard. However, empirical studies have shown that
messages actually come from therapists, not clients, falsifying theory. FC supporters reject the
evidence, claiming that skepticism undermines trust and that FC only works when not scrutinized—
making their belief unfalsifiable.
Scientists form a community:
Merton’s scientific norms: (p15)
1. Universalism: anyone can do research regardless of your background
2. Communality: researchers form a community, the results belong to the group, general public
3. Disinterestedness: scientist should do research to find answers to problems, questions, goal
is to expand knowledge, not to become famous or rich
4. Organized skepticism: critical approach towards each other work, reviewers read the article
before publication
Fundamental versus applied research:
o Basic, fundamental research: expand knowledge, improve theory
o Translational research: try to expand knowledge to make a practical application, still abstract
, o Applied research: real world setting, test practical application
o You have to start with basic research before you can go to applied research
Continuously evolving:
o Theories are continuously tested, modified, and falsified
o Research triggers follow-up research (example: impact of color on approach- and avoidance-
motivation in context (Meier et al., 2012))
Study: booklet red or bleu cover, students with booklet red color preformed worse with the test
(anagrams), color will be linked to motivation (red = stop, bleu = approach in real life)
Follow up study: color is linked to motivation but it depends on situations: in romantic context red is
connected to approach : 2 groups, told them, you will have a date or interview to asses level of
intelligence, showed picture of person in other room (bleu or red shirt), measured how quickly you
walk (approach = fast, avoid = slow), results above →context mattered, expanded theory →couldn’t
be replicated
o Theories are continuously tested, modified, and falsified (most are eventually falsificated)
o Research triggers follow-up research (example: impact of color on approach- and avoidance-
motivation in context (Meier et al., 2012))
Publishing:
o Manuscripts are submitted to scientific journals (e.g., Nature, Science, Psychological Bulletin)
o Peer-review process
➢ Parties involved include editor, reviewers, authors
➢ Reject, revise and resubmit, accept
Publications are important for your career, if you look for a job they will look at how many, about
what your publications are →your articles should be good, but you also need a lot of them, that
causes a problem
Les 1:
Introduction to scientific reasoning
Overview lecture:
1. Psychology is a way of thinking (chapter 1)
2. Sources of information (chapter 2)
Chapter 1: psychology is a way of thinking
Everything psychologists learn is knowledge acquired through scientific research.
Producing versus consuming research:
Slide 4: research producer / research consumer →how to help patients, which treatment to use? You
need to be able to read and understand studies
Example to illustrate the importance of the research consumer role (slide 5):
o Griet works as a therapist but doesn’t have a degree in psychology, she claims she doesn’t
need it because she has studied other things
o she referred to a study that a type of therapy works, but if you look closely you can see that
the study isn’t good: only 10-20 dns, no control group
Study shows that you can predict the future, with experimental evidence
o The study looks good: list of words, memorize, tell which words you remember, selected
words random that people had to write down →the words that were selected were the same
words the people remembered = predicted the future
o did a lot of studies but didn’t report all of them, analyze the data but changed it
o unable to replicate, triggered replication crisis
o Critical mindset is essential
o Not all published research is correct or robust
o Replication crisis in psychology: you cannot replicate a lot of psychological studies
The benefits of being a good consumer:
Example 1:
The "Scared Straight" program, aimed at deterring at-risk youth from crime by exposing them to the
harsh realities of prison life, may seem like a logical intervention. However, research has shown that
the program is not only ineffective but may actually increase criminal behavior among participants.
Several studies, including randomized controlled trials, found that those who attended Scared
Straight programs committed more crimes than those who did not. In some cases, crime rates among
participants increased by up to 20%. Due to these findings, the U.S. Department of Justice warns
against such programs, and the Juvenile Justice and Delinquency Prevention Act of 1974 was
amended to prohibit youth offenders from interacting with adult inmates in jails and prisons. This
,example underscores the importance of relying on empirical evidence rather than intuition when
evaluating intervention programs.
Example 2:
Michael Mrazek and his colleagues (2013) conducted a study to investigate the effects of mindfulness
on test performance. Participants were randomly assigned to either a 2-week mindfulness training
course or a 2-week nutrition course. At the end of the training, those who practiced mindfulness
showed less mind-wandering and improved their GRE scores compared to their previous
performance. In contrast, the nutrition course participants did not show these improvements.
This study suggests that mindfulness—focusing on the present moment without judgment—can
enhance concentration and academic performance. The findings support the idea that mindfulness
could be a useful tool for students looking to improve their study skills and test results.
How scientists work:
o Science is based on empiricism
o Scientists test theories
o Scientists work on fundamental and applied problems
o Science is continuously evolving
o Scientists publish their findings in scientific journals
o Scientists communicate with the general public via journalists
Empiricism:
o Empirical method is based on data obtained through:
➢ Our senses (sight, hearing, touch)
➢ Instruments that assist our senses (thermometer, questionnaires, timer)
o Empiricists aim to do research in a systematic (same way with all dns), rigorous (transparent
about how to collect data, others can be critical), and replicable (repeat) manner
o Empiricism is not based on own experiences, intuition, or authority figures
Scientists test theories: the theory-data cycle (p13):
1. Theory Formation – A theory is a set of general
principles explaining relationships between variables.
2. Research Questions & Hypotheses – The theory
guides researchers in forming specific research questions
and testable hypotheses.
3. Study Design & Data Collection – Researchers design
studies and collect data to test their hypotheses.
4. Data Analysis & Interpretation – If the data support
the hypothesis, confidence in the theory increases. If the
data contradict it, the theory is revised, or the research
design is improved.
5. Preregistration – To ensure transparency, researchers
ideally state their expected outcomes before collecting
data.
This process is cyclical, meaning theories are continuously tested, refined, or adjusted based on
new evidence
,Note:
There is a difference between exploratory (inductive) and confirmatory (deductive) research!
Confirmatory (deductive): Most start with theory and test this with hypothesis, is data in line with
hypothesis or not, change theory or study
Exploratory (inductive): learn how people think
Harlow (1958) (slide 10): Cupboard theory (attachment to the person who is feeding you) vs. Contact
comfort theory (attachment to the person gives you love, comfort) : study baby monkeys with 2
cages (bottle milk and hard or soft, warm figure and no food →monkeys go to the comfort cage
→study: 2 theories, hypothesis, data collection, conclusion
Scientists test theories:
o Characteristics of good theories
➢ Supported by data
➢ Falsifiable
➢ Parsimonious (“Occam’s razor”) (zuinig)
o Examples of non-falsifiable theories: (non-falsifiable = pseudoscience)
➢ Facilitated communication threatment believers (it will only work if you believe in it
→cant falsify )
➢ See book “De ongelovige Thomas heeft een punt”
o Theories are evaluated based on all available evidence
➢ A theory can never be “proven”, but it can be falsified (single confirming finding
cannot prove a theory, single disconfirming finding does not lead researchers to scrap
a theory. If hypothesis isn’t supported, they might say that data are inconsistent with
a theory. Scientists may troubleshoot the study instead of rejecting the theory.)
➢ Replication is crucial
➢ The simplest theory is the one that we will choose if we have more than one
Example pseudoscience: Facilitated Communication (FC) is technique where therapists guide dns with
developmental disorders to communicate via keyboard. However, empirical studies have shown that
messages actually come from therapists, not clients, falsifying theory. FC supporters reject the
evidence, claiming that skepticism undermines trust and that FC only works when not scrutinized—
making their belief unfalsifiable.
Scientists form a community:
Merton’s scientific norms: (p15)
1. Universalism: anyone can do research regardless of your background
2. Communality: researchers form a community, the results belong to the group, general public
3. Disinterestedness: scientist should do research to find answers to problems, questions, goal
is to expand knowledge, not to become famous or rich
4. Organized skepticism: critical approach towards each other work, reviewers read the article
before publication
Fundamental versus applied research:
o Basic, fundamental research: expand knowledge, improve theory
o Translational research: try to expand knowledge to make a practical application, still abstract
, o Applied research: real world setting, test practical application
o You have to start with basic research before you can go to applied research
Continuously evolving:
o Theories are continuously tested, modified, and falsified
o Research triggers follow-up research (example: impact of color on approach- and avoidance-
motivation in context (Meier et al., 2012))
Study: booklet red or bleu cover, students with booklet red color preformed worse with the test
(anagrams), color will be linked to motivation (red = stop, bleu = approach in real life)
Follow up study: color is linked to motivation but it depends on situations: in romantic context red is
connected to approach : 2 groups, told them, you will have a date or interview to asses level of
intelligence, showed picture of person in other room (bleu or red shirt), measured how quickly you
walk (approach = fast, avoid = slow), results above →context mattered, expanded theory →couldn’t
be replicated
o Theories are continuously tested, modified, and falsified (most are eventually falsificated)
o Research triggers follow-up research (example: impact of color on approach- and avoidance-
motivation in context (Meier et al., 2012))
Publishing:
o Manuscripts are submitted to scientific journals (e.g., Nature, Science, Psychological Bulletin)
o Peer-review process
➢ Parties involved include editor, reviewers, authors
➢ Reject, revise and resubmit, accept
Publications are important for your career, if you look for a job they will look at how many, about
what your publications are →your articles should be good, but you also need a lot of them, that
causes a problem
