Scientific Methods

by Richard D. Jarrard

SCIENTIFIC METHODS
an online book
Richard D. Jarrard
Dept. of Geology and Geophysics, University of Utah
r.jarrard@utah.edu

This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported

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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