Baseline

Baseline is a reference point or starting point used for measurement and comparison across different fields. It defines the initial conditions from which change is assessed and helps ensure consistency across observations or plans.

In project management, the baseline typically refers to the approved plan for scope, schedule, and cost. It provides a standard against which actual performance is measured, and changes usually require formal change control.

In experimental design and clinical research, a baseline measurement is taken before an intervention. Baseline data characterize participants and serve as a comparator for post-intervention outcomes; they also support randomization and adjustment in analysis.

In statistics and data science, a baseline model is a simple reference model used to benchmark more complex methods. In longitudinal studies, baseline values denote initial observations that anchor subsequent analysis.

In typography, the baseline is the line on which most characters sit. Descenders extend below the baseline, while ascenders rise above it.

In surveying and geodesy, a baseline is the measured distance between two points that serves as a reference for further measurements, map production, and triangulation.