Last update:
05-Aug-2017

In order to acquire appropriate knowledge for taking rational decisions in the health sciences, design and conduct of reliable and valid studies is necessary. The results of such studies constitute the evidence, or otherwise, the knowledge that health professionals use in order to provide the best health care. Health professionals need to design and conduct studies with the minimum bias, and then apply the conclusions of these studies in their clinical practice. In brief, the fundamental principles of design of a study include: Determination of the scientific hypothesis, choice of the appropriate kind of study, application of an appropriate sampling method, sample size estimation, choice of the appropriate measurement tools and application of ethical principles. Knowledge of the fundamental principles of research methodology, epidemiology and statistics is necessary in order for studies to be designed and conducted with minimum bias. As the content of these three scientific branches is broad and complex, time, patience and effort are needed by the researchers to fulfil the aims of their studies.

Key words: Design, Ethical issues, Sample size, Sampling, Scientific hypothesis, Study.