Overview
This lecture introduces the scientific method, its key components, and variables, with emphasis on its non-linear structure and the importance of controls and peer review in scientific research.
The Scientific Method
- The scientific method is a step-by-step process for conducting experiments and observations to advance scientific knowledge.
- It is best viewed as a circular, not strictly linear, process with ongoing cycles of observation, hypothesis, experimentation, and analysis.
- Typical steps include asking questions, making observations, forming a hypothesis, designing experiments, troubleshooting procedures, and analyzing and communicating results.
- Scientific research rarely follows a strict sequence; scientists often revisit and revise stages as needed.
Experimental Design & Variables
- The independent variable is the factor intentionally changed in an experiment, usually plotted on the x-axis of a graph.
- The dependent variable is the factor measured for change, affected by the independent variable, and plotted on the y-axis.
- A control group provides a baseline to compare the effects of the independent variable.
- Controlled experiments help minimize errors and increase reliability of results.
Types of Control Groups
- Positive control groups use a variable that is expected to produce a known response, ensuring the system works and checking for false negatives.
- Negative control groups are set up where no response is expected, helping identify false positives in the experiment.
Peer Review and Scientific Communication
- The peer review process evaluates the quality and validity of research by anonymous experts before publication.
- Peer review helps detect errors and minimize bias, ensuring the reliability of scientific findings.
- Scientific discussions and debates are common over data interpretation but do not invalidate the foundational processes.
Key Terms & Definitions
- Scientific Method — a systematic approach to research using observation, experimentation, and analysis.
- Independent Variable — the variable changed by the experimenter.
- Dependent Variable — the variable measured and affected by changes in the independent variable.
- Control Group — a baseline group used for comparison in experiments.
- Positive Control — a group expected to show a response, confirming the system works.
- Negative Control — a group not expected to show a response, used to detect false positives.
- Peer Review — evaluation of scientific work by others in the field for quality and accuracy.
Action Items / Next Steps
- Review your textbook or class materials for diagrams of the scientific method.
- Practice identifying independent, dependent, and control variables in example experiments.