# Scientific Methods

SCIENTIFIC METHODS an online book Richard D. Jarrard Dept. of Geology and Geophysics, University of Utah r.jarrard@utah.edu
License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/ or
The original native digital pdf file is on-line at: https://archive.org/details/sm_all_cc
Scientific Methods is an online book about the techniques and processes of science and the experience of being a scientist. This book is written by a scientist for scientists. My hope is that it will be browsed by scientists (including graduate students) and read by undergraduates.
Why am I publishing this book online, despite having a willing soft-cover publisher? The main reason is wider availability to readers. A typical science book has a publication run of ~2000 copies, then it goes out of print. Additional factors include educational use and ease of revision. I admit that I would have enjoyed saying that I earned ~25¢/hour by writing this book.
CONTENTS :
| 1. Introduction | 1 |
| Overview | 1 |
| Thumbnail History of Scientific Methods | 3 |
| Myth of a Scientific Method | 12 |
| Scientific Methods | 12 |
| SCIENTIFIC TOOLBOX | |
| 2. Variables | 15 |
| Statistics | 15 |
| Errors | 16 |
| Precision > Accuracy > Reliability | 17 |
| Random and Systematic Errors | 18 |
| Representative Sampling | 18 |
| Replication and Confirmation | 20 |
| Probability | 20 |
| Sampling Distribution for One Variable | 21 |
| Histograms | 22 |
| Normal Distribution | 23 |
| Mean & Standard Deviation | 23 |
| Normal Distribution Function | 24 |
| Weighted Mean | 26 |
| 95% Confidence Limits on Mean | 26 |
| How Many Measurements are Needed? | 27 |
| Propagation of Errors | 28 |
| Non-Normal Distributions | 29 |
| Normality Tests | 30 |
| Rejecting Anomalous Data | 32 |
| Median, Range, & 95% Confidence Limits | 33 |
| Examples | 37 ​ |
| 3. Induction and Pattern Recognition | 42 |
| Types of Explanation | 43 |
| Coincidence | 45 |
| Correlation | 46 |
| Examples | 47 |
| Crossplots | 50 |
| Plotting Hints | 52 |
| Extrapolation and Interpolation | 53 |
| Correlation Statistics | 55 |
| Nonlinear Relationships | 58 |
| Correlation Conclusions | 60 |
| Perspectives on Causality | 60 |
| Mill's Canons: Five Inductive Methods | 64 |
| Method of Agreement | 65 |
| Method of Difference | 66 |
| Joint Method of Agreement & Difference | 67 |
| Method of Concomitant Variations | 67 |
| Method of Residues | 67 |
| Correlation or Causality? | 68 |
| 4. Deduction and Logic | 71 |
| Logic | 72 |
| Deduction vs. Induction | 73 |
| Deductive Logic | 74 |
| Classification Statements | 75 |
| Deductive Aids: Venn Diagrams and Substitution | 76 |
| Logically Equivalent Statements | 78 |
| Relationships among Statements | 80 |
| Syllogisms | 82 |
| Categorical Syllogisms | 83 |
| Hypothetical Syllogisms | 85 |
| Pitfalls: Fallacious Arguments | 86 |
| Fallacies Resulting from Problems in a Premise | 88 |
| Fallacies Employing Extraneous Other Evidence | 90 |
| Faulty Link between Premises & Conclusion | 92 |
| Case-dependent Relationship between Parts & Whole | 94 |
| 5. Experimental Techniques | 97 |
| Observational versus Experimental Science | 98 |
| Seizing an Opportunity | 101 |
| Experimental Equipment | 101 |
| Prototypes and Pilot Studies | 102 |
| Troubleshooting and Search Procedures | 104 |
| Problem: Find a Needle in a Haystack | 109 |
| Problem: Search for the Top Quark | 110 |
| Tips on Experimental Design and Execution | 110 |
| Pitfalls of Experimental Design | 116 |
| Control of Variables | 117 |
| Problem: the Noisy Widgetometer | 120 |
| Computation and Information Handling | 121 |
| LIVING SCIENCE | |
| 6. The Myth of Objectivity | 125 |
| Perception: Case Studies | 125 |
| Perception, Memory, and Schemata | 131 |
| Postmodernism | 135 |
| Pitfalls of Subjectivity | 137 |
| Experimental Design | 137 ​ |
| Experiment Execution | 138 |
| Data Interpretation | 140 |
| Publication | 140 |
| Pitfall Examples | 141 |
| Group Objectivity | 143 |
| 7. Evidence Evaluation and Scientific Progress | 146 |
| Judgment Values | 147 |
| Evaluation Aids | 151 |
| Confirmation and Refutation of Hypotheses | 156 |
| Power of Evidence | 157 |
| Hypothesis Modification | 159 |
| Paradigm and Scientific Revolution | 161 |
| Pitfalls of Evidence Evaluation | 164 |
| Hidden Influence of Prior Theory on Evidence Evaluation | 164 |
| Incremental Hypotheses and Discoveries | 165 |
| 'Fight or Flight' Reaction to New Ideas | 165 |
| Confusing the Package and Product | 166 |
| Pitfall Examples | 166 |
| 8. Insight | 168 |
| Role of Insight in Science | 169 |
| Characteristics of Insight | 170 |
| Conditions Favoring Insight | 171 |
| Obstacles to Insight | 173 |
| The Royal Way | 175 |
| How Does Insight Work? | 176 |
| Alternative Paths to Insight | 178 |
| Unexpected Results | 178 |
| Transfer from other Disciplines | 178 |
| Breakthroughs by Amateurs: the Outsider Perspective | 179 |
| From Puzzle Solving… | 180 |
| …To Mystical Experience | 181 |
| 9. The Scientist's World | 183 |
| Scientist and Lay Person | 183 |
| Science and Society | 184 |
| Science and the Arts | 187 |
| Science and Pseudoscience | 187 |
| Applied and Basic Research | 189 |
| Conflict: Applied vs. Basic Research | 189 |
| Changing Goals for Applied and Basic Research | 191 |
| Resolution: Bridging the Gap | 192 |
| Big Science versus Little Science | 193 |
| Ego and the Scientific Pecking Order | 194 |
| 10. The Scientist | 197 |
| Scientists' Characteristics | 197 |
| Essential Characteristics | 197 |
| Common Characteristics | 199 |
| Cooperation or Competition? | 202 |
| Science Ethics | 205 |
| Publication | 207 |
| A Scientist's Life: Changing Motivations | 210 |
| Process and Product | 211 |
| References | 214 |
| Name Index | 225 |
| Subject Index | 228 |
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