Experiment!

Dr Öivind Andersson is Assistant Professor in the Department of Energy Sciences at Lund Universitytransparent engines and works with optical measurements in transparent engines. His responsibilities include supervision of several Ph.D. students thus providing opportunities to reflect on how to develop their abilities as experimenters and he has developed and taught a faculty-common Ph.D. course on experimental methodology that partly forms the basis for the proposed book. Before joining Lund University he worked for seven years for the Volvo Car Corporation, both with optical and traditional engine experiments and his duties varied from product development to research tasks. He monitored several of the company's research projects at universities, and was often engaged in discussions about how the outcome of the efforts invested in their experiments could be improved. In 2006 he received the Henry Ford European Technical Achievement Award, for development of a "Low Temperature Concept for Low Emission Diesel Engines", with L. Jacobsson, J. Somhorst, and A. Lööf. He has authored and co-authored 20 scientific publications.

Preface xi Part One Understanding the World 1 You, the Discoverer 3 1.1 Venturing into the Unknown 4 1.2 Embarking on a Ph.D 5 1.3 The Art of Discovery 5 1.4 About this Book 7 1.5 How to Use this Book 8 Further Reading 10 References 10 2 What is Science? 11 2.1 Characteristics of the Scientific Approach 11 2.2 The Inductive Method 14 2.3 The Hypothetico-Deductive Method 16 2.4 Consequences of Falsification 19 2.5 The Role of Confirmation 21 2.6 Perception is Personal 23 2.7 The Scientific Community 29 2.8 Summary 30 Further Reading 31 References 31 3 Science s Childhood 33 3.1 Infancy 33 3.2 Ionian Dawn 34 3.3 Divine Mathematics 38 3.4 Adolescence Revolution! 41 3.5 The Children of the Revolution 47 3.6 Summary 50 Further Reading 50 References 51 4 Science Inclined to Experiment 53 4.1 Galileo s Important Experiment 54 4.2 Experiment or Hoax? 56 4.3 Reconstructing the Experiment 58 4.4 Getting the Swing of Things 60 4.5 The Message from the Plane 62 4.6 Summary 63 References 64 5 Scientists, Engineers and Other Poets 65 5.1 Research and Development 65 5.2 Characteristics of Research 68 5.3 Building Theories 70 5.4 The Relationship between Theory and Reality 75 5.5 Creativity 77 5.6 Summary 79 Further Reading 80 References 80 Part Two Interfering with the World 6 Experiment! 83 6.1 What is an Experiment? 83 6.2 Questions, Answers and Experiments 85 6.3 A Gallery of Experiments 88 6.4 Reflections on the Exhibition 108 6.5 Summary 110 Further Reading 110 References 112 7 Basic Statistics 113 7.1 The Role of Statistics in Data Analysis 113 7.2 Populations and Samples 115 7.3 Descriptive Statistics 116 7.4 Probability Distribution 122 7.5 The Central Limit Effect 126 7.6 Normal Probability Plots 129 7.7 Confidence Intervals 132 7.8 The t-Distribution 134 7.9 Summary 136 Further Reading 137 References 138 8 Statistics for Experiments 139 8.1 A Teatime Experiment 139 8.2 The Importance of Randomization 141 8.3 One-Sided and Two-Sided Tests 142 8.4 The t-Test for One Sample 143 8.5 The Power of a Test 148 8.6 Comparing Two Samples 150 8.7 Analysis of Variance (ANOVA) 155 8.8 A Measurement System Analysis 159 8.9 Other Useful Hypothesis Tests 163 8.10 Interpreting p-Values 164 8.11 Correlation 165 8.12 Regression Modeling 167 8.13 Summary 171 Further Reading 172 References 173 9 Experimental Design 175 9.1 Statistics and the Scientific Method 175 9.2 Designs with One Categorical Factor 176 9.3 Several Categorical Factors: the Full Factorial Design 178 9.4 Are Interactions Important? 186 9.5 Factor Screening: Fractional Factorial Designs 187 9.6 Determining the Confounding Pattern 188 9.7 Design Resolution 190 9.8 Working with Screening Designs 191 9.9 Continuous Factors: Regression and Response Surface Methods 195 9.10 Summary 207 Further Reading 208 References 209 10 Phase I: Planning 211 10.1 The Three Phases of Research 211 10.2 Experiment 1: Visual Orientation in a Beetle 213 10.3 Experiment 2: Lift-Off Length in a Diesel Engine 216 10.4 Finding Out What is Not Known 218 10.5 Determining the Scope 221 10.6 Tools for Generating Hypotheses 222 10.7 Thought Experiments 227 10.8 Planning Checklist 229 10.9 Summary 231 References 233 11 Phase II: Data Collection 235 11.1 Generating Understanding from Data 235 11.2 Measurement Uncertainty 236 11.3 Developing a Measurement System 238 11.4 Measurement System Analysis 244 11.5 The Data Collection Plan 248 11.6 Summary 251 Further Reading 252 References 252 12 Phase III: Analysis and Synthesis 253 12.1 Turning Data into Information 253 12.2 Graphical Analysis 256 12.3 Mathematical Analysis 259 12.4 Writing a Scientific Paper 260 12.5 Writing a Ph.D. Thesis 264 12.6 Farewell 266 12.7 Summary 266 Further Reading 266 References 267 Appendix 269 Standard Normal Probabilities 269 Probability Points for the t-Distribution 270 Index 271