Psych

What is psychology?
• Psychology – the scientific study of behavior and
mental processes
• Psychology is based on empirical evidence, that
which is gathered from experience or observation.
• In AICE psychology, there are six main research
methods that you need to know.
• They are experiments, self-reports, case studies,
observations, correlations, and longitudinal
designs.

Types of Data
• The data that psychologists collect may be either
qualitative or quantitative.
• Quantitative data consists of numerical information
(quantity) or simple text that can easily be converted
to numbers.
• Qualitative data is expressed in rich data through
long blocks of text (such as interviews or field
notes).
• Some studies use both approaches in the same
research. This is called mixed methods.

Aims and Hypotheses
• The aim of the study is the researcher’s intention
(what they plan to do).
• Example – The aim of Bandura’s experiment is to determine
whether children will imitate an aggressive adult model.

Aims and Hypotheses
• Hypotheses are experimental predictions which are
tested.
• An experimental hypothesis predicts a relationship
between the IV and the DV.
• These can be one-tailed (directional) or two-tailed (non-
directional)
• Researchers also formulate a null hypothesis,
which states that the IV will have NO EFFECT on
the DV.
• This is because inferential statistics must be run on the null
hypothesis.
• Psychologists NEVER accept the null. They either reject or
fail to reject it.

Sample vs. Population
• Population – the entire group that you wish to find out
about
• Usually the population is very large, for example all
American citizens.
• It would be very expensive and time-consuming to
test most populations.
• Sample – a small group of participants gathered from
the total number available
• Random sampling is the best way to ensure a
sample is representative.

Sampling Techniques
• Random sampling – Every member of a population
has an equal chance to be chosen for the sample.
• Opportunity sampling – Participants are chosen out of
convenience (i.e. proximity to the researcher)
• Volunteer (self-selected) sampling – Participants
choose to take part in the study (i.e. responding to an
ad)
• Opportunity and volunteer samples limit
generalization to the population.

Experiments
• An experiment occurs when one variable is changed
and everything else is controlled to establish
causation.
• There are three types of variables that
are important:
– Independent variable (IV) – What is
manipulated by the researcher
– Dependent variable (DV) – The outcome
variable or what is measured
– Confounding variable – Anything other than the
IV that might affect the DV

Operational Definitions
• Each variable should have an operational definition –
a precise way that it is being specified for the purpose
of the study.
• Example – Using BMI >30 as an operational definition for
obesity.

Experiments
• A true experiment takes place in a lab with meticulous
control over confounds.
• These can be artificial and lack ecological validity.
• Field experiments occur when a researcher
manipulates variables in the real world.
• These can be limited by a lack of control over confounding
variables.
• Quasi-experiments (also called natural experiments)
involve an independent variable that can’t truly be
manipulated.
– Examples include gender, race, age, socioeconomic status,
etc.

Types of Experimental Designs
• Independent Samples – Separate groups that each
get a different level of the independent variable
• The groups are typically randomly assigned.
• Matched Pairs – Separate groups that are deliberately
made equal in a key trait
• Repeated Measures – The
same group gets each level
of the independent variable

Reliability vs Validity
• Quantitative research is highly focused on reliability
and validity. This is because the ease of collecting
data leads to constant replication.
• Reliability refers to the consistency of psychological
research. There are several methods to assess
reliability:
• Test-retest reliability – scores are consistent over
time
• Interobserver reliability – different graders give
consistent scores

Validity
• Validity refers to the ability of research to measure
what it is supposed to measure.
• Internal validity – How well is the environment
controlled to prevent confounds?
• External validity – To what extent can data be
generalized outside the study?
• Ecological validity - Can the data be transferred to real-life
situations?
• Population validity - Do the results generalize to other
groups?

Internal Validity
• Internal validity refers to the control of confounds in an
experiment.
• Participant variables – traits of the individuals in the study
(often controlled through random allocation)
• Situational variables – factors of the environment of the study
(often controlled through standardization)
• Uncontrolled variables – those that the researcher cannot
control (i.e. what happens at home during a field study)

Internal Validity
• The main experimental control for participant variables
is random allocation into groups. The goal is to make
the two groups as equal as possible without introducing
experimenter bias.
– The experimental group
actually receives the treatment.
– A control group does not
receive the treatment but is
treated just like the
experimental group.

Issues with Repeated Measures
• Repeated measures designs must use
counterbalancing – The levels of the IV should not be
presented in the same order for everyone.
• If this does not happen, they may suffer from practice or
fatigue effects:
• Practice Effect – A person does better on the second trial
because of the experience gained on the first trial.
• Fatigue Effect – A person does worse on the second trial
because they get tired or bored with the experiment.

The Placebo Effect
• Placebo effect – a change in behavior resulting from a
belief that the treatment will have an effect.
• In drug studies, the placebo is a sugar pill (one with no
active ingredients).
• The main technique used to control for the placebo
effect is the double-blind experiment, in which both the
subjects AND the researcher are unaware of who is in
each group.

Evaluation of Experiments
• What’s good?
– True experiments establish causation
– More researcher control than any other method
– Often replicated to check for reliability

Evaluation of Experiments
• What’s bad?
– Only true experiments establish causation. The other types
cannot due to lack of control over confounds or no true
manipulation of the IV.
– Experiments can be time-consuming and expensive
– True experiments are often artificial and lack ecological validity
– True experiments often utilize opportunity sampling, which
hurts their generalization

Self-reports
• Survey / Questionnaire - gathering information by
asking a fixed set of questions to many people.
• The questionnaire method enables a large sample in
a short period of time.
• Questionnaires are typically paper-and-pencil or
online.
• Open and closed questions can be utilized.
• Open questions are broad and can be answered in detail,
while closed questions have a limited number of options.

Self-Reports
• Interviews – a qualitative method that enables
researchers to obtain rich data through questioning a
small number of participants.
• Interviews are typically
conducted in-person or
over the phone.
• Interviews can also
incorporate open or
closed questions.

Types of Interviews
• Structured – the interviewer sticks to the planned
questions with no deviance.
• Semi-structured – questions are planned but the
interviewer can “go off script” and ask additional
questions.
• Unstructured – questions
are not planned and the
person being interviewed
guides the conversation

Evaluation of Self-Reports
• What’s good?
– The ability to surveys to gather a lot of data very quickly
– Generally high in ecological validity as self-reports measure
real-life variables
– Surveys can be filled out anonymously, decreasing demand
characteristics
– Interviews can be used to investigate rare or sensitive
phenomena.

Evaluation of Self-Reports
• What’s bad?
– Strong potential for participant biases (such as social
desirability and acquiescence)
– Volunteer bias may occur as those who willingly take a survey
or interview may not be “normal”
– Survey construction is sometimes poor and can suffer from
wording effects, leading questions, order effects, etc.
– No assurance that participants are telling the truth or
remembering events correctly
– Surveys can only establish correlation

Ethical Issues
• Ethics – standards for responsible or moral behavior
• All psychological studies must abide by certain ethical
standards outlined by the American Psychological
Association (APA).
• Any proposed research must first be approved by an
Institutional Review Board (IRB).

Ethical Issues
• Informed consent - participants must be briefed on the
study and allowed to decide whether or not they choose
to proceed.
• Deception, or the use of trickery, should be avoided
whenever possible.
• Researchers should minimize physiological or
psychological harm as a result of the experiment.
• Debriefing - Revealing the true nature of the study after
participants have completed.

Ethical Issues
• Right to withdraw - subjects are allowed to stop
participating or remove their data at any time.
• Confidentiality - Researchers must ensure that subjects
remain anonymous.
• Privacy – The subject should not
be interfered with after the study
has concluded.

Animal Ethics
• Just like humans, steps should be taken to minimize
harm (and maximize benefit)
• Replacement – If there is a way to avoid the use of
animals, it should be followed
• Species – Researchers should avoid treating one
species superior to another.
• Numbers – Animal research should use low sample
sizes
• Procedures should address pain,
suffering / distress, housing,
reward, deprivation and aversive
stimuli