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The Nature of Science and Statistical Analysis

Nature of Science

  • Science seeks to understand the natural world through observation and reasoning.

  • Starts with observations (e.g., classification of life, genome sequencing).

Reasoning in Science

  • Deductive reasoning: general principles to specific predictions.

  • Inductive reasoning: specific observations to general conclusions.

Systematic Approach to Science

  • Steps: Observation, Hypothesis formation, Prediction, Experimentation, Conclusion.

Hypothesis

  • A hypothesis is a potential explanation for observations.

  • Must be tested for validity and can be refined with new data.

  • Should produce predictions that can be tested.

Experimentation

  • Designed to test hypotheses, focusing on one variable.

  • Involves test and control experiments.

Designing Experiments

  • Identify variables: Independent (manipulated), Dependent (measured), Controlled (constant).

  • Design procedure and make predictions based on the hypothesis.

  • Consider replication and control conditions.

Statistics Overview

  • Data: Information/results from experiments.

  • Descriptive statistics: summarizing main features (mean, median, mode, etc.).

  • Inferential statistics: drawing conclusions from data with random variation.

Descriptive Statistics Definitions

  • Mean: average value.

  • Median: middle value in sorted list.

  • Mode: most frequent value.

  • Range: difference between highest and lowest values.

  • Variance: spread measurement of data.

  • Standard Deviation: square root of variance.

  • Standard Error: accuracy of an estimate.

Inferential Statistics Applications

  • Assess relationships between variables.

  • Examples: t-test, ANOVA, correlation, regression analysis.

Data Presentation

  • Tables: for multiple dependent variables.

  • Graphs: for visual relationships (line and bar graphs).

    • Line graphs: for continuous data.

    • Bar graphs: for discrete categories.

Philosophy of Science

  • Reductionism: breaks complex processes into simpler parts.

  • Systems science: focuses on emergent properties.

Scientific Theory

  • Body of interconnected concepts backed by evidence.

  • Unlike general theory, it indicates strong certainty rather than guesswork.