Chapter Two – The Ways & Means of Psychology
Part 1: The Scientific Method in Psychology (30)
- The Scientific Method consists of a set of rules that dictate the general procedure a scientist must
follow in his or her research; a set of rules that governs the collection and analysis of data gained
through observational studies or experiments.
- Psychologists conduct three major types of scientific research: naturalistic observation and clinical
observation, correlation studies, and experiments.
Naturalistic Observation and Clinical Observation (31)
- Naturalistic observation: observation of people or animals in their natural environment. This method is
least formal and constrained by fewest rules.
- Clinical observation: the observation of the behaviour of people who are undergoing diagnosis or
- Naturalistic provides foundation for natural sciences
- Examples: Darwin’s observation and classification of animals for theory of evolution & Maria
Montessori used this method for her ideas about child development by watching children in a classroom
& Paul Broca suggested that language was located in a specific region of the brain after treatment of a
Correlational Studies (31)
- Correlational Study: The examination of relations between two or more measurements of behaviour or
other characteristics of people or other animals.
- Observational in nature but involves more formal measurement – of environmental events, of
individuals’ physical and social characteristics, and of their behaviour.
- Experiments: a study in which the researcher changes the value of an independent variable and
observes whether this manipulation affects the value of a dependent variable. Only experiments can
confirm the existence of cause-and-effect relations among variables.
Five Rules of the Scientific Method for Experiments (31)
1) Identify the problem and formulate hypothetical cause-and-effect relations among variables.
2) Design the experiments. The independent variable must be manipulated and the dependent variable
must be observed. Independent variable must be controlled to ensure that it is the only variable that is
causing the dependent variable to change.
3) Perform the experiment.
4) Evaluate the hypothesis by examining the data from the study. Do the results support the hypothesis,
or do they suggest that it is wrong?
5) Communicate the results. Example: writing and publishing a journal or share findings at conference
and conventions to other psychologists.
Step #1: Identifying the Problem: Getting an Idea for Research (32)
- Psychological research in Canada has historically been supported three major research-funding
agencies of the Canadian government: the Natural Sciences and Engineering Research Council, the
Social Sciences and Humanities Research Council, and the Canadian Institutes of Health Research.
- Hypotheses, a statement, usually designed to be tested by an experiment, that tentatively expresses
a cause-and-effect relationship two or more events, literally means suggestion in Greek. It is the
starting point of any study and if phrased as a general statement.
- A theory is a set of statements that describes and explains known facts, proposes relations among
variables, and makes new predictions. It is sort of an elaborate form of the hypothesis. A good theory
generates testable hypotheses – hypotheses that can potentially be supported or proved wrong by
scientific research. Example: Freud theorized that conflicts between id and superego were significant
determinants of personality and behaviour, but there is no way to observe or measure this and
therefore not a testable hypothesis.
- Scientific journal named Psychological Review that publishes old problems in new ways by showing
how findings that did not appear to be related can be explained by a single concept.
Naturalistic & Clinical Observations as Sources of Hypotheses and Theories (33)
- Naturalists are people who carefully observe animals in their natural environment, disturbing them as
little as possible. Naturalistic observations are then are what naturalists see and record. Sometimes,
they do interfere with a situation or natural setting. Example: survey study.
- Clinical psychologists record important patterns of behaviour in detail descriptions known as case
studies – detailed description of an individual’s behaviour during the course of clinical treatment or
diagnosis. The clinician cannot interfere with the treatment regime prescribed for the patient. They too
can manipulate treatment given to patient with desire of producing a more beneficial response and
results would be published in a case study but would be classified as an experiment.
- Both clinical and naturalistic observation can form the basis of hypotheses about causes of behaviour;
however, clinical psychologists do not stay in the background but instead try to change the patient’s
- Survey study: A study of people’s responses to standardized questions.
Step #2: Designing an Experiment (34)
- Variables, operational definitions, Control of independent variables.
- Naturalistic and clinical observations allow psychologists to classify behaviours into categories and
provide hypothetical explanations, only experiments can determine if the explanations are correct.
- Variable: things that can vary in value. Anything that can differ in amount, degree, or presence versus
absence is a variable.
- Manipulation: setting the values of an independent variable in an experiment to see whether the
value of another variable is affected.
- The results of experimental manipulations and measurements of variables help us evaluate
- For there must be two groups: experimental group and control group.
- Experimental group: a group of participants in an experiment, the members of which are exposed to
particular value of the independent variable.
- Control group: a comparison group used in an experiment, the members of which are exposed to the
naturally occurring or zero value of the independent variable.
- Provided that our two groups of volunteers were alike at the start of the experiment, which is usually
accomplished by randomly assigning volunteers to the two groups, we could attribute any differences in
detection ability to the experimental manipulation of expectation.
- Independent variable: the variable that is manipulated in an experiment as a means of determining