Theoretische introductie in onderzoeksmethoden: Research Methods in Psychology
H1. Psychology is a way of thinking Psychologists are empiricists, they base conclusions on systematic observations. They don’t
simply think intuitively about behavior, cognition and emotion; they know wat they know
because they have conducted studies on people and animals acting in their natural
environments or in specially designed situations. Consumers of research like reading about research so they can apply it to their work,
hobbies or relationships. Producers of research are fascinated by the research process, they
study, document, observe and analyse. In practice, many psychologists engage in both roles.
Researchers and consumers share a commitment to the practice of empiricism.
The producer role is important for your future coursework, but also for writing papers
following the guidelines of the American Psychological Association and for research.
Becoming a consumer is essential, you will need to develop the ability to read about
research with curiosity. Understanding research methods enables you to ask the appropriate
questions so you can evaluate information correctly. Licensure in helping professions (social worker, clinical psychologists, therapists etc.)
requires knowing the research behind evidence-bases treatments – that is, therapies that
are supported by research. We always need empirical evidence to test the efficacy of our interventions. Being a skilled
consumer of information can inform you about other programs that might work. Skills in
research methods will help you become a better consumer of studies, so you can decide
when the research supports some programs but not others. The fundamental ways psychologists approach their work goes in 4 steps.
1. They act as empiricists, they do not base conclusions on intuition or on casual
Empiricism involves using evidence from the senses or from instruments that assist
the senses as the basis for conclusions.
2. They test theories: the theory-data cycle. Scientists collect data to test, change, or
update their theories. When you take systematic steps to solve a problem, you are
participating in something similar to what scientists do in the theory-data cycle.
A theory is a set of statements that describes general principles about how variables relate
to one another. A hypothesis is the specific outcome the researcher expects to observe in a
study if the theory is accurate. Data are a set of observations that can support or challenge
the theory. The best theories are:
- Supported by data from research studies. Scientists need to conduct multiple studies,
using a variety of methods, to address different aspects of their theories.
- Falsifiable. A theory must lead to hypotheses that, when tested, could actually fail to
support the theory.
- Have parsimony. If two theories explain the data equally well, most scientists will opt
for the simpler, more parsimonious theory.
Theories do not prove anything. At most, scientists will say that some data support or are
consistent with a theory. Scientists evaluate their theories based on the weight of the
evidence, for and against. The empirical method can be used for both applied and basic research questions.
Applied research is done with a practical problem in mind; the researchers conduct their
work in a particular real-world context.
Basic research is not intended to address a specific, practical problem: the goal is to enhance
the general body of knowledge.
Translational research is the use of lessons from basic research to develop and test
applications to health care or other forms of treatment and intervention. Psychological scientists rarely conduct a single investigation and then stop. Instead, each
study leads them to ask a new question. 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 paper gets send to other experts to
tell the editor about its virtues and flaws. A lot of papers get summarized by journalists, so they can give it a bigger audience and
change the writing into nontechnical terms. Psychologists can benefit when journalists
publicize their research, the general public can learn what psychologists really do and they
are additionally able to make changes in their lifes. The benefits of science writing depend on: journalists need to report on the most important
scientific stories and they must describe the research accurately. The Mozart effect provides
an example of how journalists might misrepresent science when they write for a popular
audience. H2. Sources of Information: Why research is best and how to find it Our own experiences are powerful sources of information. Often, too, we base our opinions
on the experiences of friends and family. Reasons not to base beliefs solely on personal
1. Experience has no comparison group. A comparison group enables us to compare
what would happen both with and without the thing we are interested in.
2. Experience is confounded. In real-world situations, there are several possible
explanations for an outcome. In research these are called confounds. For a personal
experience, it is hard to isolate variables. In a research setting, scientists can use
3. Research is better than experience. There is a lot more control for example for
confounds, but there is also the possibility to insert a comparison group.
4. Research is probabilistic. The findings are not expected to explain all cases all of the
time. The conclusions of research are meant to explain a certain proportion of the
Five examples of biased reasoning:
1. Being swayed by a good story. Accepting a conclusion because it makes sense or feels
natural. Sometimes a good story will turn out to be accurate, but it’s important to be
aware of the limitations of intuition.
2. Being persuaded by what comes easily to mind. The availability heuristic. Things that
pop up easily in our mind tend to guide our thinking.
3. Failing to think about what we cannot see. 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, is a name for our failure to consider
appropriate comparison groups.
The availability heuristic plays a role in the present/present bias because instances in
the present/present cell of a comparison stand out.
4. Focusing on the evidence we like best. The tendency to look only at information that
agrees with what we already believe is called the confirmation bias.
5. Biased about being biased. We have what’s called a bias blind spot, the belief that
we are unlikely to fall prey to other biases previously described.
To be an empiricist, you must strive to interpret the data you collect in an objective way.
Psychological scientists usually publish their research in three kinds of sources: as articles in
scholarly journals, as a chapter in an edited book or as a full-length scholarly book. Journal articles are written for an audience of other psychological scientists and psychology
students. They can be either empirical or review articles.
Empirical articles report, for the first time, the results of a research study.
Review articles provide a summary of all the published studies that have been done in one
research area. Sometimes a review article uses a quantitative technique called meta-
analysis, which combines the results of many studies and gives a number that summarizes
the magnitude, or the effect size, of a relationship. Before being published both empirical and review articles need to be peer-reviewed. An edited book is a collection of chapters on a common topic; each chapter is written by a
In some other disciplines, full-length books are a common way for scholars to publish their
work. However, psychologists do not write many full-length scientific books for an audience
of other psychologists. Popular databases for empirical research are PsycINFO and google scholar. Components of an empirical journal article:
- Abstract. A concise summary of the article including the hypotheses, method and
- Introduction. Explanation of the topic of the study and its background.
H1. Psychology is a way of thinking
H2. Sources of Information: Why research is best and how to find it
H3. Three claims, four validities: Interrogation Tools for Consumers of Research
H4. Ethical guidelines for psychology research
H5. Identifying Good Measurement
H6. Surveys and observations: describing what people do
H7. Sampling: Estimating the frequency of behaviors and beliefs
H8. Bivariate correlational research
H9. Multivariate correlation research
H10. Introduction to simple experiments
H11. More on Experiments: Confounding and Obscuring variables
H12. Experiments with more than one independent variable
H13. Quasi-experiments and small-N designs
H14. Replication, generalization, and the real world.