Psych Chapter 2
• The Scientific Approach to Behaviour:
o Goals of the Scientific Enterprise
o Steps in a Scientific Investigation
o Advantages of the Scientific Approach
• Experimental Research:
o Independent and Dependant Variables
o Experimental and Control Groups
o Extraneous Variables
o Variations in Designing Experiments
o Advantages and Disadvantages of Experimental Research
• Descriptive/Correctional Research:
o Naturalistic Observation
o Case Studies
o Advantages and Disadvantages of Descriptive/Correctional Research
• Statistics and Research:
o Descriptive Statistics
o Inferential Statistics
• Evaluating Research:
o Sampling Bias
o Placebo Effects
o Distortions in Self-Report Data
o Experimenter Bias
• Internet Research
www.notesolution.com The Scientific Approach to Behaviour
Goals in a Scientific Enterprise
1. Measurement and Description - You must develop techniques to measure behaviour
clearly and precisely.
2. Understanding and Prediction - Hypothesis. A hypothesis is a tentative statement
about the relationship between two or more variables. Variables are any measurable
conditions, events, characteristics, or behaviours that are controlled or observed in a
3. Application and Control - A theory is a system of interrelated ideas used to explain a
set of observations. Empirical Test. Experiment should be able to be replicated. Also
variables should be controlled and try to leave no room for catalysts thwarting
Steps in a Scientific Investigation:
1. Formulate a Testable Hypothesis - Scientific Hypotheses must be formulated
precisely, and the variables under study must be clearly defined. Researchers
achieve these clear formulations by providing operational definitions of the relevant
variables. An Operational Definition describes the actions or operations that will be
used to measure or control a variable.
2. Select the Research Method and Design the Study - Find out the research method
(Experiments, Naturalistic Observations, Surveys etc.), then find out how you are
going to execute study (What kind of experiment, who participants are going to be,
how many participants, etc.). Participants, or Subjects, are the people or animals
whose behaviour is systematically studied.
3. Collect the Data - Collect Data. Data collection techniques are procedures for
making empirical observations and measurements. Techniques below.
1. Direct Observation - Observers trained to watch and record behaviours as
objectively and precisely as possible.
2. Questionnaire - Subjects administered a series of written questions designed
to obtain information about attitudes, opinions, and specific aspects of their
3. Interview - Face to face dialogue conducted to obtain information about
specific aspects of subjects behaviour.
4. Psychological Test - Subjects are administered a standardized measure to
obtain a sample of their behaviour. Used to assess mental abilities or
personality traitors usually.
5. Physiological Recording - Instrument used to monitor and record specific
physiological process in a subject (Like blood pressure ,heart rate, brain
6. Examination of Archival Records - Analyze existing institutional records such
as census, economic, medical, legal, educational, and business records.
www.notesolution.com Advantages of the Scientific Approach
• Two Major Advantages:
1. It provides clarity and precision.
2. Relative intolerance to error.;;
Independent and Dependent Variables
• We want to know how X affects Y. X is the independent, and Y is the
• An independent variable is a condition or event that an experimenter varies
in order to see its impact on another variable.
• The dependent variable is the variable that is thought to be affected by
manipulation of the independent variable.
Experimental and Control Groups
• When conducting an experiment, there are usually two groups who are
treated differently with regard to the independent variable.
o Experimental group: Consists of the subjects who receive some special
treatment in regard to the independent variable.
o Control Group: Consists of similar subjects who do not receive special
treatment given to the experimental group.
• Extraneous Variables are variables other than the independent variable that
seem likely to influence the dependent variable in a specific study.
• Confounding of Variables occurs when two variables are linked together in a
way that makes it difficult to sort out their specific effects.
• Random Assignment of subjects occurs when all subjects have an equal
chance of being assigned to any group or condition in the study.
Variations in Designing Experiments
www.notesolution.com • Sometimes it is advantageous to use only one group of subjects who serve as
their own control group. This stops extraneous variables.
• Manipulating multiple independent variables.
• Multiple dependent variables.
Advantages and Disadvantages of Experimental Research
• Permits conclusions about cause-and-effect relationships between variables.
• One problem is experiments are often artificial since everything is controlled
and the environment is constructed.
• This method can’t be used to explore some research questions which aren’t
ethical or practical.
• Naturalistic Observation is when a researcher engages in careful observation
of behaviour without intervening directly with the subjects.
• Allows subjects to be in a non-artificial environment; however the
experiments often have trouble trying to not interfere with the subjects.
• A case study is an in depth investigation of an individual subject.
• When studying victims of suicide, the case studies a