Research producers and consumers share a commitment to empiricism (answering psychological
questions with direct, formal observations) and to communicating with others about what they have
learned.
➔ Empiricism involves using evidence from the senses (sight, hearing, touch) or from
instruments that assist the senses as the basis for conclusions.
Evidence-based treatment: A psychotherapy technique whose effectiveness has been supported
by empirical research.
In the theory-data cycle, scientists collect data to test, change, or update their theories
➔ A theory is a set of statements—as simple as possible—that describes general principles
about how variables relate to one another
➔ A hypothesis, or prediction, is stated in terms of the study design. It’s the specific outcome
the researcher will observe in a study if the theory is accurate.
➔ Data are a set of observations. 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.
Deductie: nieuwe kennis afleiden uit zekere waarheden
Inductie: nieuwe kennis verkrijgen uit waarnemingen
➔ Deductie leidt tot zekere nieuwe kennis; Inductieve generalisaties kunnen fout zijn.
A theory should lead to hypotheses that, when tested, could fail to support the theory—in other
words, falsifiability is a characteristic of good theories
Merton’s four norms that people in scientific community strive to follow:
● Universalism: Scientific claims are judged by their quality and the same criteria, regardless of
the researcher’s status or background.
● Communality: Scientific knowledge belongs to the community and should be openly and
transparently shared with other scientists and the public.
● Disinterestedness: Scientists aim to find the truth based on the data, without letting
personal beliefs, politics, profit, or prestige influence their conclusions.
● Organized skepticism: Scientists critically question all ideas, including their own theories
and accepted beliefs, and always look for evidence.
Basic research: Research aimed at increasing general knowledge and understanding, without
focusing on a specific practical problem.
Applied research: Research aimed at solving a specific practical problem in a real-world context.
Translational research: Research that applies findings from basic research to develop and test
practical treatments, interventions, or applications.
,CHAPTER 2: Sources of Information: Why Research Is
Best and How to Find It
PERSONAL EXPERIENCE
A comparison group enables us to compare what would happen both with and without the thing we
are interested in
By not testing any comparison groups, the surgeons failed to follow Merton’s norm of organized
skepticism: They assumed that their treatment was working instead of looking for the evidence
Experience doesn’t have a comparison group. You might believe that your visit to a “rage room” made
you feel better (compared with sitting quietly), but you do not have comparison data when you only
live through one experience.
● Confounds: Alternative factors or explanations that can make it difficult to determine what
actually caused a result, because several things may have changed at the same time.
● Systematic comparison: In a controlled study, researchers compare different groups to get
an objective overall picture instead of relying on individual experiences. This allows them to
see patterns that participants themselves may not notice.
● Probabilistic nature of research: Research findings describe general patterns that apply to
many people, but not necessarily to every individual case. Your own experience can therefore
differ from the research without meaning that the research is wrong.
INTUITION
One example of a bias in our thinking is accepting a conclusion just because it makes sense or feels
natural. Another bias in thinking is 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.
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. The tendency to look only at information that agrees with what we
want to believe is called the confirmation bias.
We have what’s called a bias blind spot, the belief that we are unlikely to fall prey to the other biases
previously described. Most of us think we are less biased than others, so when we notice that our
own view of a situation is different from that of somebody else, we conclude that “I’m the objective
one here” and “you are the biased one.
Empirical journal articles report, for the first time, the results of an (empirical) research study.
Empirical articles contain details about the study’s method, the statistical tests used, and the results
of the study.
Review journal articles summarize and integrate 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.
CHAPTER 3: Three Claims, Four Validities: Interrogation
Tools for Consumers of Research
A variable is something that can change or have different values.
A constant is something that stays the same.
Researchers can measure or manipulate variables. A measured variable is simply observed and
recorded as it naturally occurs (eg. height). A manipulated variable is a variable a researcher
controls, usually by assigning study participants to the different levels of that variable.
➔ Some variables cannot be manipulated, they can only be measured, like age.
➔ Some variables, however, can be either manipulated or measured, depending on the goals of
a study.
A variable can be described in two ways:
● Conceptual variable (construct): The general concept being studied.
➔ Conceptual definition: A theoretical explanation of what the concept means. Een construct
is niet observeerbaar (intelligentie, ervaren stress, agressie, enz.). Hoe kunnen we er dan iets
over zeggen?
● Operational definition (operationalization): Operationele definitie: een definitie in termen
van procedures waarmee het construct wordt gemeten of gemanipuleerd
○ Example: Satisfaction with life can be measured using questionnaire items.
○ Perseverance can be measured by how long a child continues an activity despite it
being slow or difficult.
A claim is an argument someone is trying to make.
● Frequentie-claim: b.v. 13.2% van de automobilisten is rond middernacht onder invloed van
alcohol
● Associatie-claim: Show that two variables are related but do not necessarily mean one
causes the other. b.v. hoe hoger de bloedalcoholconcentratie, hoe slechter de rijprestatie
➔ correlational study: the variables are measured and the relationship between them
is tested. Correlatiecoëfficiënt: Een maat voor de lineaire samenhang tussen twee
variabelen
➔ positieve correlatie: hoe meer X, hoe meer Y.
➔ negatieve correlatie: hoe meer X, hoe minder Y.
➔ zero association = no correlation between variables in the study.
● Causale claim: b.v. een hogere bloedalcoholconcentratie veroorzaakt een slechtere
rijprestatie. A veroorzaakt B als en alleen als:
1. A en B covariëren of correleren (covariantie)
2. A voorafgaat aan B (temporele precedentie)
3. Alternatieve verklaringen zijn uitgesloten (uitsluiting van
derde-variabeleverklaringen)