Experiment!

Experiments are the most effective way to learn about the world. By cleverly interfering with something to see how it reacts we are able to find out how it works. In contrast to passive observation, experimenting provides us with data relevant to our research and thus less time and effort is spent separating relevant from irrelevant information.  The art of experimentation is often learnt by doing, so an intuitive understanding of the experimental method usually evolves gradually through years of trial and error. This book speeds up the journey for the reader to becoming a proficient experimenter.  Organized in two parts, this unique text begins by providing a general introduction to the scientific approach to experimentation.  It then describes the processes and tools required, including the relevant statistical and experimental methods.   Towards the end of the book a methodology is presented, which leads the reader through the three phases of an experiment: ‘Planning’, ‘Data Collection’, and ‘Analysis and Synthesis’.  Experiment! Provides an excellent introduction to the methodology and implementation of experimentation in the natural, engineering and medical sciences Puts practical tools into scientific context Features a number of selected actual experiments to explore what are the key characteristics of good experiments Includes examples and exercises in every chapter  This book focuses on general research skills, such as adopting a scientific mindset, learning how to plan meaningful experiments and understanding the fundamentals of collecting and interpreting data. It is directed to anyone engaged in experiments, especially Ph.D. and masters students just starting to create and develop their own experiments.

Preface xi Part One Understanding the World 1 You, the Discoverer 3 11 Venturing into the Unknown 4 12 Embarking on a PhD 5 13 The Art of Discovery 5 14 About this Book 7 15 How to Use this Book 8 Further Reading 10 References 10 2 What is Science? 11 21 Characteristics of the Scientific Approach 11 22 The Inductive Method 14 23 The Hypothetico-Deductive Method 16 24 Consequences of Falsification 19 25 The Role of Confirmation 21 26 Perception is Personal 23 27 The Scientific Community 29 28 Summary 30 Further Reading 31 References 31 3 Science’s Childhood 33 31 Infancy 33 32 Ionian Dawn 34 33 Divine Mathematics 38 34 Adolescence – Revolution! 41 35 The Children of the Revolution 47 36 Summary 50 Further Reading 50 References 51 4 Science Inclined to Experiment 53 41 Galileo’s Important Experiment 54 42 Experiment or Hoax? 56 43 Reconstructing the Experiment 58 44 Getting the Swing of Things 60 45 The Message from the Plane 62 46 Summary 63 References 64 5 Scientists, Engineers and Other Poets 65 51 Research and Development 65 52 Characteristics of Research 68 53 Building Theories 70 54 The Relationship between Theory and Reality 75 55 Creativity 77 56 Summary 79 Further Reading 80 References 80 Part Two Interfering with the World 6 Experiment! 83 61 What is an Experiment? 83 62 Questions, Answers and Experiments 85 63 A Gallery of Experiments 88 64 Reflections on the Exhibition 108 65 Summary 110 Further Reading 110 References 112 7 Basic Statistics 113 71 The Role of Statistics in Data Analysis 113 72 Populations and Samples 115 73 Descriptive Statistics 116 74 Probability Distribution 122 75 The Central Limit Effect 126 76 Normal Probability Plots 129 77 Confidence Intervals 132 78 The t-Distribution 134 79 Summary 136 Further Reading 137 References 138 8 Statistics for Experiments 139 81 A Teatime Experiment 139 82 The Importance of Randomization 141 83 One-Sided and Two-Sided Tests 142 84 The t-Test for One Sample 143 85 The Power of a Test 148 86 Comparing Two Samples 150 87 Analysis of Variance (ANOVA) 155 88 A Measurement System Analysis 159 89 Other Useful Hypothesis Tests 163 810 Interpreting p-Values 164 811 Correlation 165 812 Regression Modeling 167 813 Summary 171 Further Reading 172 References 173 9 Experimental Design 175 91 Statistics and the Scientific Method 175 92 Designs with One Categorical Factor 176 93 Several Categorical Factors: the Full Factorial Design 178 94 Are Interactions Important? 186 95 Factor Screening: Fractional Factorial Designs 187 96 Determining the Confounding Pattern 188 97 Design Resolution 190 98 Working with Screening Designs 191 99 Continuous Factors: Regression and Response Surface Methods 195 910 Summary 207 Further Reading 208 References 209 10 Phase I: Planning 211 101 The Three Phases of Research 211 102 Experiment 1: Visual Orientation in a Beetle 213 103 Experiment 2: Lift-Off Length in a Diesel Engine 216 104 Finding Out What is Not Known 218 105 Determining the Scope 221 106 Tools for Generating Hypotheses 222 107 Thought Experiments 227 108 Planning Checklist 229 109 Summary 231 References 233 11 Phase II: Data Collection 235 111 Generating Understanding from Data 235 112 Measurement Uncertainty 236 113 Developing a Measurement System 238 114 Measurement System Analysis 244 115 The Data Collection Plan 248 116 Summary 251 Further Reading 252 References 252 12 Phase III: Analysis and Synthesis 253 121 Turning Data into Information 253 122 Graphical Analysis 256 123 Mathematical Analysis 259 124 Writing a Scientific Paper 260 125 Writing a PhD Thesis 264 126 Farewell 266 127 Summary 266 Further Reading 266 References 267 Appendix 269 Standard Normal Probabilities 269 Probability Points for the t-Distribution 270 Index 271