. Author manuscript; available in PMC: 2018 Mar 1.

Published in final edited form as: SLAS Discov. 2017 Jan 6;22(3):213–237. doi: 10.1177/2472555216682725

Table 2.

Selected Definitions

Term	Definition
Biologically Relevant Heterogeneity	General term for heterogeneity detected or measured at some scale (level) of a biological system (molecule, cell, tissue, organ, organism) after correcting for any instrumental “systems response” variations, as well as sample preparation.
Population Heterogeneity	Variation in some phenotype(s) among individuals in a population at a single time point. Requires measurements of many individuals in a population.
Spatial Heterogeneity	Variation in some variable(s) at different spatial locations within a sample. Requires a set of measurements at different spatial locations
Temporal Heterogeneity	Variation in some variable(s) measured as a function of time. Requires a set of measurements at different time points.
Quantitative Systems Pharmacology (QSP)	Determining the mechanism(s) of disease progression and mechanism(s) of action of drugs on multi-scale systems through iterative and integrated computational and experimental methods to optimize the development of therapeutic strategies.
Precision Medicine	Development and use of individual or combinations of features that tell clinicians about risk of disease, selection of the best treatment, and likely disease course, including response to treatment for a specific patient.
Pseudotime	Quantitative measures of biological progression¹²⁷
Heteroscedasticity	Unequal variance in the distribution (with respect to an independent variable)