Lecture #1 01/28/2014
Authority: Someone tells us that a statement is true
Reason: Using thought and logic to decide that something is true.
Empiricism: Observing the world to decide that something is true
Case of Clever Hans
A form of involuntary and unconscious cuing. The term refers to a horse (Kluge Hans, referred to in the
literature as "Clever Hans") who responded to questions requiring mathematical calculations by tapping his
hoof. Pfungst launched an independent investigation of Hans ability with the help of M. von Osten.
Conclusion: Hans was indeed clever, but he did not have any “humanlike” intellectual abilities.
When we say we are “skeptical,” we mean that we must see compelling evidence before we believe.
skepticism is a method, not a position.
Connectivity Principle: (stanovich, 2010)
New theories in science must make contact with previous established empirical fact.
New findings should usually fit established scientific theories.
For a new theory to be adopted, it must explain old, wellestablished findings, explain previously
unexplained findings, and point to as of yet unknown findings.
Bat and Ball problem:
A bat and ball cost $1.10, the bat costs one dollar more than the ball.
How much does the ball cost?
1.05$ for the bat, 0.05$ for the ball.
The cognitive miser: People tend to consider very little information when they need to take decisions;
they avoid thinking. Vividness problem (Stanovich, 2010)
When faced with a problemsolving or decisionmaking decision situation, people retrieve from memory the
information that seems relevant to the situation at hand
For scientists, testimonial evidence is useless, because:
the sample of the “study” is 1
cause cannot be determined
multiple alternative explanations are available
Other common examples: diets, medical treatments, selfhelp, learning…
Unfortunately, pseudoscientists and charlatans use testimonials profusely to deceive people.
The confirmation bias is a pervasive cognitive phenomenon (Baron, 2008).
People may continue to hold beliefs for which there is no empirical support (e.g., astrology) because they
only seek confirmatory evidence.
The search for counterevidence is a more powerful way of testing theories and ideas
Missing knowledge that may lead people to take suboptimal or inappropriate decisions (Stanovich, 2009).
Examples from the domain of probability:
Insensitivity to sample size (base rate neglect) – Nurse vs. hockey player problem
Insensitivity to prior probability of outcome – Hospital problem
“Gambler’s fallacy” – coin toss problem The Forer effect and fortune telling
If some ideas have been demonstrated to be false, why do they stick around?
Key insight: “…a belief may spread without necessarily being true or helping the human
being who holds the belief in any way.” (Stanovich, 2009, p. 162).
Properties of the ideas (see memetics, Blackmore, 1999):
Interesting (e.g., ghost stories)
Selfreplicating properties (e.g., chain emails)
desire to believe things (life after death)
need to assign a cause.
What is science?
Science is a method for acquiring knowledge that protects us against our propensity for flawed and
Empirically Solvable Problems
type of questions that scientists address are potentially answerable by means of currently available
Theoretical constructs can be operationalized Theory tested is falsifiable (Popper, 1959)
Mathematical and technological tools are available.
Structured observations that reveal something about the underlying nature of the world.
Replication and Peer Review
To be considered legitimate, research must be presented to the scientific community in a way that enables
evaluate and criticize claims and theories
to reproduce experiments
to replicate results
. Lecture #2 01/28/2014
How does Scientific research proceed?
1) Develop a question
2) Embed the question in theoretical context
4)conduct the experiment
5) Analyze data
7)communicate the results
Develop a question
Scientific research is a complex enterprise. It requires:
Conceptual and methodological expertise in a highly specialized area of knowledge
Access to the scientific community (written work and “live” contact)
Funding (for technology and human resources)
scientific research requires extensive training.
Experts in Psychology: (it takes 10 years to become an expert in any field)
Experimental psychologists (Ph. D.)
Clinical psychologists (Ph. D or D. Psy)
Many other peripheral professions have some expertise in psychology. Lecture #2 01/28/2014
Experts get their research ideas:
Sources are multiple (intuition, observation, specific problems), but mostly, researchers pursue a program
They: develop and refine methodological techniques, gather empirical data, evaluate theories.
Embed the question…
Theory: It is a set of logically organized constructs that serve to explain and predict empirical phenomena.
Construct: A scientific concept that is meaningful because it is part of a theoretical network.
Operationalization (of theoretical constructs): To establish a clear relationship between the theoretical
construct and its empirical basis in the operations producing the data.
In science, questions are answered by posing hypotheses.
Hypothesis. A provisional explanatory proposition which makes certain definite predictions concerning
Ex: if theory X is correct, then I should observe Y in the world.
An inference that draws a conclusion about a specific event on the basis of a general concept.
Conclusion follows if the structure of the argument is sound and premises are true.
An inference that builds a general explanation about a phenomenon based on a subset of observations.
The strength of the induction is proportional to that of the evidence.
Design the experiment Lecture #2 01/28/2014
There are multiple research designs. Selection depends on the state of knowledge.
Descriptive research and case studies
Nonexperimental and quasiexperimental designs
Conduct the experiment
Once the study is designed, the research conducts the experiment.
Obtains permission from Ethics Review Board
Selects and recruits participants
Collects the data
Analyze the data
Methods of characterizing or summarizing a given set of data.
Averages: mean, median, mode
Dispersion: range, variance, standard deviation
Tables, Graphs, and Figures
The aspect of statistics that deals with methods for making appropriate inferences about populations on the
basis of samples.
Safeguard against making theoretical arguments based on a “lucky” result.
For all inferential statistics, the pvalue indicaprobability that the result was obtained by chance. Lecture #2 01/28/2014
Interpret the data
Once the data have been analyzed, the researcher determines what they mean.
If the hypothesis is supported:
What do the results mean for theory?
How can the results be extended?
How can the results be applied?
If the hypothesis is not supported:
Was the methodology wrong?
Was the theory wrong?
When the research has been conducted, psychologists communicate their data and their interpretations to
the scientific community.
The main vehicles vary depending on the scientific discipline, but in psychology, they are:
Posters, Talks, Books, Peer Reviewed Journal articles.
Scientific conferences in all areas of science are organized regularly.