1. Study designs for making most of the limited resources.

Medical research is costly and requires significant effort. While intracellular research hardly follows a formal design, most data-based studies require a structural approach for optimal utilization of resources. Depending on the study's objectives and available resources, as well as the aim to obtain valid and reliable results, the design may be descriptive, employing specific sampling strategies, or analytical, exploring antecedent-outcome relationships. Analytical studies often involve designs such as randomization and blinding in clinical trials, and may use prospective, retrospective, or cross-sectional designs in observational studies. This first article in the series on biostatistics methods specifies the essential features of each design and describes the contexts in which they are most appropriate.