Methodenleer
Hoofdstuk 1 Psychology is a way of thinking
Producers of research: work as research scientists or professors
Consumers of research: reading about research so they can apply it later to work, hobbies.
In practice, psychologists are both.
Interrogating information: like a detective, a consumer of research needs to know how to ask the
right questions and evaluate a study on the basis of the answers. This book will teach you systematic
rules for interrogating research information—a skill most employers are looking for.
1. First, they act as empiricists in their investigations.
Empiricism: involves using evidence from the senses (sight, hearing, touch) or from instruments that
assist the senses (such as thermometers, timers, photographs, weight scales, and questionnaires) as
the basis for conclusions.
2. They test theories through research and, in turn, revise their theories based on the resulting data.
The Theory-Data Cycle: scientists collect data to test, change, or update their theories. Even if you
haven’t yet conducted formal research, you have probably tested ideas and hunches of your own by
asking specific questions that are grounded in theory, making predictions, and reflecting on data.
A theory is a set of statements that describes general principles about how variables relate to one
another. For example, Harlow’s theory was that contact comfort, not food, was the primary basis for
a baby’s attachment to its mother. This theory led Harlow to investigate particular kinds of
questions—he chose to pit contact comfort against food in his research.
The theory not only led to the questions but also to specific hypotheses about the answers. Notably,
one theory can lead to a large number of hypotheses because a single study is not sufficient to test
the entire theory—it is intended to test only part of it.
Data are a set of observations. Data that match the theory’s hypotheses strengthen the researcher’s
confidence in the theory. When the data do not match the theory’s hypotheses, however, those
results indicate that the theory needs to be revised or the research design needs to be improved
If scientists take their role as empiricists seriously, they are not justified in making generalizations
about phenomena they have not observed. The possible existence of one unobserved nonblack
raven prevents us from saying we’ve proved that all ravens are black.
Instead of saying “prove,” scientists say that a study’s data support or are consistent with a theory. A
single confirming finding cannot prove a theory. Similarly, a single disconfirming finding does not lead
researchers to scrap a theory. If a hypothesis is not supported, they might say that data are
inconsistent with a theory
Scientists conduct multiple investigations, replicating the original study. A replication means the
study is conducted again to test whether the result is consistent. Scientists therefore evaluate their
theories based on the weight of the evidence—the collection of studies, including replications, of the
same theory.
Falsifiability is a characteristic of good theories: A feature of a scientific theory, in which it is possible
to collect data that will indicate that the theory is wrong. To be truly scientific, researchers must take
risks, including being prepared to accept data that do not support their theory. Practitioners must be
open to such risk as well so they can use techniques that actually work.
3. They follow norms in the scientific community that prioritize objectivity and fairness.
,By being open to falsification and skeptically testing every assumption, science can become self-
correcting; that is, it discovers its own mistaken theories and corrects them.
• Universalism: scientific claims are evaluated according to their merit, independent of the
researcher’s credentials or reputation.
• Communality: scientific claims are evaluated according to their merit, independent of the
researcher’s credentials or reputation. Shared with the public.
• Disinterestedness: scientists strive to discover the truth whatever it is; they are not swayed
by conviction, idealism, politics, or profit. Not personally invested.
• Organized skepticism: scientists question everything, including their own theories, widely
accepted ideas, and ancient wisdom.
4. They take an empirical approach to both applied research and basic research.
Applied research: Research whose goal is to find a solution to a particular real-world problem. For
example, if a school district’s new method of teaching language arts is working better than the
former one?
Basic research: Research whose goal is to enhance the general body of knowledge, rather than to
address a specific, practical problem. Basic researchers might want to understand the structure of
the visual system.
Translational research: Research that uses knowledge derived from basic research to develop and
test solutions to real-world problems. Translational researchers attempt to translate the findings of
basic research into applied areas. For example, basic research on the biochemistry of cell membranes
might be translated into a new drug for schizophrenia.
5. Psychologists make their work public.
When scientists want to tell the scientific world about the results of their research, they write a
paper and submit it to a scientific journal. The articles in a scientific journal are peer-reviewed. The
journal editor sends the paper to three or four experts on the subject. The experts tell the editor
about the work’s virtues and flaws and the editor, considering these reviews, decides whether the
paper deserves to be published in the journal.
Journalism, in contrast, is a secondhand report about the research, written by journalists or
laypeople. A journalist might become interested in a psychology study and turns the research into a
news story by summarizing it for a popular audience, giving it an interesting headline and using
nontechnical terms. Science journalism fulfills the communality norm of science by allowing scientists
to share potentially valuable work with the general public. Science journalism is easy to access, and
understanding it does not require specialized education. However, in their effort to tell an engaging,
clickable story, journalists might overstate the research or get the details wrong. Mozart effect:
Journalists sometimes misrepresent research findings. Exaggerated reports of the Mozart effect even
inspired a line of consumer products for children.
Hoofdstuk 2 Sources of Information: Why Research Is Best and How to
Find It
People’s beliefs can be based on their own experience, on their intuition, on authorities, or on
controlled research. Of these, research information is the most accurate source of knowledge. This
chapter discusses three sources of evidence for people’s beliefs— experience, intuition, and
authority—and compares them to a superior source of evidence: empirical research.
THE RESEARCH VERSUS YOUR EXPERIENCE
Experience has no comparison group
, • Beliefs based on personal experience may not be accurate. One reason is that personal
experience usually does not involve a comparison group. In contrast, research explicitly asks:
Compared to what? A comparison group enables us to compare what would happen both
with and without the thing we are interested in.
Example: From 1890 to the 1970s, most surgeons simply assumed that radical mastectomy
was a better treatment for breast cancer. But they only had data on their own procedure;
they never collected any data on comparison treatments.
Experience is confounded
• In real-world situations, there are several possible explanations for an outcome. In research,
these alternative explanations are called confounds. Confounded can also mean confused.
Essentially, a confound occurs when you think one thing caused an outcome but in fact other
things changed, too, so you are confused about what the cause really was. In daily life, many
things are going on at once, and it is impossible to know which factor is responsible for a
particular outcome. Personal experience is often confounded. In contrast, researchers can
closely control for confounding factors→ scientists can use careful controls to be sure they
are changing only one factor at a time.
Research is better than experience
• Research has an advantage over experience because researchers design studies that include
appropriate comparison groups. In a controlled study, researchers can set up the conditions
to include at least one comparison group. Contrast the researcher’s larger view with the
more subjective view, in which each person consults only their own experience. The
researcher thus has a privileged view—the view from the outside, including all possible
comparison groups. In contrast, when you are the one acting in the situation, yours is a view
from the inside, and you only see one possible condition. Researchers can also control for
potential confounds.
Research Results Are Probabilistic
• Conclusions based on research are probabilistic: Research findings cannot predict or explain
all cases all the time; instead, they aim to predict or explain a high proportion of cases.
Individual exceptions to research findings do not nullify the results. Thus, for instance, even
though radical mastectomy does not cure cancer, some women did become cancer-free after
the surgery. Those patients who recovered do not change the conclusion derived from all of
the data. Similarly, just because there is a strong general trend (that Honda Fits are reliable),
it doesn’t mean your Honda will be reliable too. The research may suggest a strong
probability that your Honda will be reliable, but the prediction is not perfect.
THE RESEARCH VERSUS YOUR INTUITION
A way to reach a conclusion is intuition. Using our hunches about what seems “natural,” or
attempting to think about things “logically.” While we may believe our intuition is a good source of
information, it can lead us to make less effective decisions.
Ways that intuition can be biased:
Being swayed by a good story
• Intuition is a flawed source of information because it is affected by biases in thinking. People
are likely to accept an explanation that makes sense intuitively (makes sense/feels natural),
even if it is not true. When empirical evidence contradicts what your common sense tells
you, be ready to adjust your beliefs on the basis of the research. Automatically believing a
story that seems to make sense can lead you astray.
Being persuaded by what comes easily to the mind
• People can overestimate how often something happens if they consider only readily available
thoughts, those that come to mind most easily. The availability heuristic, which states that
things that pop up easily in our mind tend to guide our thinking. When events or memories
are vivid, recent, or memorable, they come to mind more easily, leading us to overestimate
how often things happen. →A professor may complain that “everybody” uses a cell phone
, during their class, when in fact only one or two students do so; it’s just that their annoying
behavior stands out.
Failing to think about what we cannot see
• People find it easier to notice what is present than what is absent. When people forget to
look at the information that would falsify their belief, they may see relationships that aren’t
there. When testing relationships, we often fail to look for absences; in contrast, it is easy to
notice what is present. This tendency, referred to as the present/present bias, reflects our
failure to consider appropriate comparison groups. → Surgeons focused on patients who
received the surgery (treatment was “present”) and recovered (recovery was “present”) but
did not fully account for those who did not recover (treatment was “present” but recovery
was “absent”) or consider other treatments (treatment was “absent”).
Focusing on evidence we like best
• Intuition is also subject to confirmation bias. We seek out evidence that confirms our initial
ideas and fail to seek out evidence that can disconfirm them. Merton’s norm of organized
skepticism means that scientists should make a habit of questioning everything and seek
evidence both for and against their ideas. →A therapist suspects her client has an anxiety
disorder. What kinds of questions should she be asking that would both potentially confirm
and potentially disconfirm her hypothesis?
Biased about being biased
• We all seem to have a bias blind spot and believe we are less biased than everyone else. it
can make it difficult for us to initiate the scientific theory-data cycle. We might say, “I don’t
need to test this conclusion; I already know it is correct.” Part of learning to be a scientist is
learning not to use feelings of confidence as evidence for the truth of our beliefs.
The Intuitive Thinker Versus the Scientific Reasoner
• Scientific researchers are aware of their potential for biased reasoning, so they create special
situations in which they can systematically observe behavior. They create comparison
groups, consider all the data, and allow the data to change their beliefs.
TRUSTING AUTHORITIES ON THE SUBJECT
• Authorities may attempt to convince us to accept their claims. If their claims are based on
their own experience or intuition, we should probably not accept them. If they use well-
conducted studies to support their claims, we can be more confident about taking their
advice. Before taking the advice of authorities, ask yourself about the source of their ideas.
Did the authority systematically and objectively compare different conditions, as a
researcher would do? However, authorities can also base their advice on their own
experience or intuition, just like the rest of us. And they, too, might present only the studies
that support their own side.
FINDING AND READING THE RESEARCH
• Tools for finding research in psychology include the online database PsycINFO, available
through academic libraries. You can also use Google Scholar or the websites of researchers.
• Journal articles, chapters in edited books, and full-length books should be read with a
purpose by asking: What is the theoretical argument? What is the evidence? What do the
data say?
• Popular media articles and books can be good sources of information about psychology
research, as long as you think critically. Journalists might not always cover psychology
research accurately. You can compare a popular media story to the original empirical article
to be sure.
• Disinformation is news that is deliberately created to mislead or provoke. Many people
believe news that is demonstrably false. Think critically and verify popular Internet sources.
Types of Disinformation. Some disinformation is completely false. Other disinformation is
more subtle: It might attribute false quotes to real people or use a real quote in a false
