Scientific knowledge is the body of knowledge that comes from the interpretation of the evidence of the material and objective data of the different research settings. The knowledge is, therefore, constituted by the innumerable theories acquired through previous studies according to a systematic and rigorous process. This leads us to unequivocally refer to the scientific progress which is a deserved success of scientists all over the world, as well as to the significant contribution of science to the economic, social and cultural development of mankind.This book is written with the aim of facilitating the understanding of research and proposing the elementary methods and principles of conducting it. It has been prepared for professionals in the agricultural and social sciences who wish to conduct surveys or investigations in the various fields of their profession.It is thus proposed in good faith to higher level students from institutes and universities in order to facilitate the writing of their dissertation.