Scientific Methods and Research Types Study Notes

Science is a method, not just a body of content. It’s about how you study reality.
Key attributes of science:
- Objective
- Systematic
- Evidence-based (observable, repeatable evidence)
Science emphasizes learning about reality through systematic observation and experimentation.
Observe a phenomenon with curiosity and critical thinking: ask why it is the way it is. This is the starting point of the scientific method.

Definition: The ability to think clearly, rationally, and independently.
Quote (James, 1890):
- "Everyone knows what attention is"
- "It is taking possession of the mind, in clear and vivid form, of one out of what seems several simultaneously possible objects or trains of thought. Focalization, concentration of consciousness are of its essence. It implies a withdrawal from some things in order to deal effectively with others."
Critical thinking steps (to evaluate claims):
- What am I being asked to access or believe?
- What evidence supports this position?
- What other ways can this evidence be interpreted?
- What other evidence do I need?
- What is the most reasonable conclusion?
Practicing Critical Thinking (example)
- Kross et al., 2013 study summary:
- 82 college students were texted 5 times a day and answered questions about their mood and Facebook use (0-100 scale).
- Finding: As students used Facebook more, participants reported more negative mood.
- Practices taught: same critical-thinking questions listed above (reiterated in the study context).
Practical exercise connection: use the same five-step reflection to assess everyday claims.

One rule: stack cards so that they are as close as possible to the top surface.
This serves as a simple context to apply critical-thinking habits (observation, hypothesis, and evaluation of constraints).

Science is a method, not just a field of study.
It is a method of learning about reality through systematic observation and experimentation.
Characteristics:
- Objective
- Systematic
- Evidence-based (observable, repeatable evidence)

Observe a phenomenon with curiosity and critical thinking (why is it the way it is?).
Formulate or challenge a theory to explain observations.
Hypotheses and predictions:
- Hypothesis — an educated guess derived from a theory.
- Can be tested.
- Usually takes the form: “if A is true, then we will observe B.”
Test hypothesis through empirical research.
Data analysis — crunching numbers mathematically.
Statistical significance: is this result likely to be obtained by chance?
P-value: p < 0.05
Discussion & Conclusion:
- Do the data support the hypothesis?
- Use findings to revise theory and generate a new hypothesis
- Consider alternative explanations

The process steps (cyclic):
- Theory → Hypothesis → Design → Experiment → Collect & Interpret Data

Goal: Identify Relationships
Key statistic: Correlation coefficient, r
Range: -1.00 \, \le \, r \, \le \, 1.00
Interpretation: A measure of the direction and strength of the relationship between two variables
Important caveat: Correlation does not imply causation

Third variable problem: a variable may be responsible for the observed correlation between two others
Example (often cited):
- Shark attacks and ice-cream sales are correlated, but the third variable is warm weather (seasonality)
Implication: Correlation alone cannot establish causation

Goal: Determine Causation
Why it’s powerful: Experiments can directly test why something happens (cause and effect)
Key concepts:
- Independent variable (IV) — the variable that is manipulated
- Dependent variable (DV) — the variable that is measured
Groups:
- Experimental group — exposed to manipulation of the IV
- Control group — treated equally, except no manipulation

Control group and random assignment help address confounds:
- Irrelevant effects of the manipulation (e.g., receiving attention, feeling nervous) are mitigated by proper controls
- Individual differences (e.g., personalities, abilities, motivations) are controlled by random assignment

Typical challenges:
- Small samples
- Many studies rely on undergrad participants
Question to consider: What does this mean for generalizability of findings to broader populations?

Theory: A set of facts and relationships between facts that can explain and predict related phenomena.
Hypothesis: An educated guess derived from a theory, testable via empirical research.
Variable: Anything that can vary across observations or conditions.
Operational definition: How a variable will be measured in a study.
Observational method: Systematic observation to gather data.
Experimental control: Techniques to ensure that observed effects are due to manipulation of the IV and not confounds.
Statistical significance: Probability that observed results are due to chance, often assessed via the p-value.
Generalizability: Extent to which findings apply beyond the studied sample.
Third variable: An outside variable that influences both the supposed cause and effect, creating a spurious relationship.

Science is a disciplined method combining observation, theory, hypothesis testing, data analysis, and interpretation.
Critical thinking is essential at every step: questioning evidence, interpretations, and alternatives.
Descriptive, correlational, and experimental designs serve different purposes and have distinct limitations.
Always consider generalizability and potential third-variable explanations when interpreting findings.

Observational data informs theory formation and hypothesis development.
Theories generate hypotheses, which are tested by designed experiments.
Empirical results feed back to theory refinement, enabling iterative improvement of scientific understanding.