Chapter 2 – Research Methodology
Scientific inquiry = a way of finding answers to empirical questions – questions
that can be answered by observing the world and measuring aspects of it.
4 basic goals:
1. Describing what happens
2. Predicting when it happens
3. Controlling what causes it to happen
4. Explaining why it happens
Scientific Method = A systematic procedure of observing and measuring
phenomena to answer questions about what happens, when it happens, what causes
it, and why.
Reflects a dynamic interaction among 3 essential elements:
1) Theories = models of interconnected ideas and concepts that explains what
is observed and makes predictions about the future
2) Hypotheses = specific predictions of what should be observed in the world if
a theory is correct
3) Research = scientific process that involves the systematic and careful
collection of data (Objective observations or measurements)
A good theory produces a wide variety of testable hypotheses.
3 main types of study designs:
The designs differ in the extent to which the researcher has control over the
variables in the study and therefore in the extent to which the researcher can make
conclusions about causation.
A variable = something in the world that can be measured and that can vary; it can
refer to something that the experiment either measures or manipulates.
>> Involves observing and classifying behavior
Descriptive studies, often called observational studies, involve observing and noting
behavior to analyze objectively.
- Especially valuable in early stages of research, when trying to determine if a
- Takes place in a real-world setting
Disadvantages: -Errors in observation can occur because of an observer’s expectations (observer
- Observer’s presence can change the behavior being witnessed (reactivity)
2 basic types of observation:
1) Naturalistic observation – the observer remains separate from and makes no
attempt to change the situation
2) Participant observation – the researcher is involved in the situation.
>> Involves observing and classifying developmental changes that occur in the same
people over time, either with no intervention by the observer or with intervention
by the observer.
- Provide information about the effects of age on the same people, allowing
researchers to see developmental changes
- Takes a long time
- May lose participants over time
>> Involves assessing the intellectual abilities of young adults and old adults and
comparing their scores on various measures of intellectual ability.
- Faster and less expensive than longitudinal studies
- Includes the possibility that some unidentified variable is responsible for any
difference between the groups.
Observer bias = systematic errors in observation that occur because of an observer’s
Observer bias can be especially problematic if cultural norms favor inhibiting or
expressing certain behaviors. Cultural norms can affect both the participants’
actions and the way the observers perceive those actions.
Experimenter expectancy effect = when observer bias changes the behavior being
observed. To avoid experimenter expectancy effects, the person running the experiment must
be blind to or unaware of the study’s hypotheses.
>> Examines how variables are naturally related in the real world, without any
attempt by the researcher to alter them.
- Relies on naturally occurring relationships.
- May take place in a real-world setting
- Cannot be used to support causal relationships (that one thing happened to
- Cannot show the direction of the cause/effect relationship between variables
- An unidentified variable may be involved (the third variable problem)
Experiment = A study that tests causal hypotheses made by measuring and
Control (or comparison group) = The participants in a study that receive no
intervention or an intervention different from the one being studied.
Experimental (or treatment) group = the participants in a study that receive the
Independent variable = In an experiment, the condition that is manipulated by the
experimenter to examine its impact on the dependent variable.
Dependent variable = In an experiment, the measure that is affected by
manipulation of the independent variable.
Confound = anything that affects a dependent variable and may unintentionally vary
between the experimental conditions of a study.
Population = Everyone in the group the experimenter is interested in.
Sample = a subset of a population.
Selection bias = When participants in different groups in an experiment differ
systematically. Random assignment = the procedure for placing research participants into the
conditions of an experiment in which each participant has an equal chance of being
assigned to any level of the independent variable; used when the experimenter
wants to test a causal hypothesis.
Meta-analysis = A “study of studies” that combines the findings of multiple studies to
arrive at a conclusion.
Culturally sensitive research = studies that take into account the ways culture
affects thoughts, feelings and actions.