The Scientific Method

1. The Scientific Method

2. The Scientific Method: Terminology • Operational definitions are used to clarify precisely what is meant by each variable • Participants or subjects are the organisms whose behavior is systematically observed in a study • Data collection techniques allow for empirical observation and measurement • Statistics are used to analyze data and decide whether hypotheses were supported

3. More Termonology • Findings are shared through reports at scientific meetings and in scientific journals – periodicals that publish technical and scholarly material • Advantages of the scientific method: clarity of communication and relative intolerance of error • Research methods: general strategies for conducting scientific studies

4. 4 Basic Goals of Psychology • 1. describe, 2. explain, 3. predict, & 4. control behavior • Psychologists guided by basic assumptions • Events are lawful • Events are explainable • Psychologists are open-minded, but full of skepticism • Psychologists must Think Critically!!!

5. Steps in the Scientific Method • Formulate a hypothesis • Identify a hypothesis, variables, & an operational definition • Design a study • Descriptive Research Methods • Experimental Methods • Analyze the data • Use statistics • Report the findings • Describe details so others can replicate later

6. Fig 2.2 - Flowchart of steps in a scientific investigation.As illustrated in a study by Cole et al. (1996), a scientific investigation consists of a sequence of carefully planned steps, beginning with the formulation of a testable hypothesis and ending with the publication of the study, if its results are worthy of examination by other researchers.

7. Building Theories • Theory: a model, or tentative explanation • Theories are tools • Evolve and change as new evidence emerges • Self-correcting nature of the scientific enterprise

8. Fig 2.1 - Theory construction.A good theory will generate a host of testable hypotheses. In a typical study, only one or a few of these hypotheses can be evaluated. If the evidence supports the hypotheses, our confidence in the theory they were derived from generally grows. If the hypotheses are not supported, confidence in the theory decreases and revisions to the theory may be made to accommodate the new findings. If the hypotheses generated by a theory consistently fail to garner empirical support, the theory may be discarded altogether. Thus, theory construction and testing is a gradual process.

9. Science vs. Pseudoscience • Pseudoscience: theory lacking evidence or nonexistent • Violate Rule of Falsifiability: identify what could prove a claim false • Use anecdotes or testimonials • Non-empirical use of scientific principals • Misinterpretation of data • TRUE • Is it testable • Is it reliable • Is it unusual • Is it explainable

10. Using Statistics

11. Statistics • Statistics: use of mathematics to organize, summarize, & interpret numerical data • Use to justify ideas • Beware of false statistics • 50% of all statistics are made up 30% of the time.

12. Descriptive Statistics • Mathematical methods used to organize & summarize data • Frequency Distributions • Central Tendency • Variability • z Scores and the Normal Curve • Correlation

13. Inferential Statistics • Mathematical methods used to determine how likely it is that a study’s outcome is due to chance • Indicates the odds of events occurring • Statistical significance • Population and Sample Model