vi PREFACE 



to learn these things? If this book can help to start their research with fewer 

 mistakes, I shall have earned a bonus. 



There is no intention of assembling a set of instructions which, if scrupu- 

 lously followed, will guarantee success in research. Research must be a 

 creative, personal process. In our investigations we learn by our failures as 

 well as our successes. Therefore, the most effective training program is a 

 number of years of experience. On the other hand, young minds are agile 

 and imaginative and full of potential contributions. A general guide may 

 help these minds to produce sooner, to avoid some of the failures, and to 

 escape from the necessity of learning everything the hard way. 



The book is intended as a starting point rather than an end in itself. With 

 this thought in mind, most of the chapters have references to more advanced 

 discussions. Some of the advanced discussions referred to will be very diffi- 

 cult for the usual bright college freshman or sophomore to read. By introduc- 

 ing the subject in simple terms, perhaps this book can make the more ad- 

 vanced discussions easier. Some readers may object that the level of writing 

 is too low. In that case, I recommend skimming rapidly and proceeding 

 immediately to the more advanced works referred to. Anyone who can start 

 at a higher level should surely do so. If some statements seem ridiculously 

 obvious, remember that they may not be obvious to everyone. 



I have rearranged the table of Contents, that is, the order of the chap- 

 ters, several times. The problem is that the various topics are so closely 

 interrelated that it is difficult to speak of one subject without also mentioning 

 the others. Probably Experimental Design should come first, for example, 

 but the subject is difficult and can best be illustrated by examples which will 

 be unfamiliar at the beginning. The best organization, apparently, would be 

 to start in the middle and proceed in all directions. 



The final schedule of topics, then, is a compromise. The first few chapters 

 form a general introduction to quantitative, experimental biology. The next 

 major section is devoted more specifically to those techniques and instruments 

 which are so important a part of the everyday work of the laboratory. Finally, 

 the data obtainable by such techniques are treated mathematically and 

 statistically, and converted into something meaningful and useful. 



Many kind people have assisted in the preparation. A few sharp-eyed 

 former students may recognize their own data in some of the examples. 

 Many of these same students were among the best critics of most of the 

 chapters. They rarely refrained from telling me about a section that was not 

 clear. 



Dr. John D. Spikes has been helpful by providing facilities, suggestions, 

 advice, and criticism. We share many opinions, but many of them I think 

 I learned from him. To Mrs. Elizabeth T. Cole goes my gratitude for her 

 ceaseless interest and encouragement, not to mention the fact that she typed 

 most of the manuscript several times. My most generous and persistent helper 



