LU 2: Scientific Methods in Psychology
Evaluating Evidence and Thinking Critically
Scientific method provides the guidelines for scientists in all fields, including psychology, to use in evaluating discrete claims (called hypotheses) and broader theories.
allows us to reach conclusions that are very likely to be true.
The degree of probability that the conclusion is true is so great that it may be considered factual.
The claim is called a hypothesis.
Testing of hypotheses must be repeated.
Conducting Psychological Research
Population Samples
Experimenter Bias
convenience sample
representative sample
cross-cultural sample
Research Design
Observational Research Design
Naturalistic Observation
Case Study
Survey
Correlation Studies
A negative correlation (-) is produced when one
variable increases as the other decreases.
A positive correlation (+) results when both variables
increase and decrease together.
A zero or near-zero correlation means that the variables
have no relationship.
Experiments; A study in which at least one variable is manipulated (independent) and at least one other (dependent) is measured.
General Principles of Research
Ethical concerns
Informed consent
Institutional Research Board (IRB) Approval
Human Subjects and Animal Subjects
Measuring and Analyzing Results
Descriptive Statistics
Mode
Median
Mean
Variation; standard deviation
Evaluating Results: Inferential Statistics
Confidence Intervals
Probability Values
Probability Values and Statistical Significance
the width of the confidence interval is based on the sample size (the larger the better) and the standard deviation (the smaller the better)