part of directive information entity study design controlled variable 2009-03-16: work has been done on this term during during the OBI workshop winter 2009 and the current definition was considered acceptable for use in OBI. If there is a need to modify thisdefinition please notify OBI. PERSON: Alan Ruttenberg PERSON: Bjoern Peters PERSON: Chris Stoeckert WEB: http://en.wikipedia.org/wiki/Control_variable controlled variable specification In the Philly 2013 workshop the label was chosen to distinguish it from "controlled variable" as used in statistical modelling In a study in which gene expression is measured in patients between 8 month to 4 years old that have mild or severe malaria and in which the hypothesis is that gene expression in that age group is a function of disease status, age is a controlled variable. 2/2/2009 Original definition: Controlled variables are also important to identify in experiments. They are the variables that are kept constant to prevent their influence on the effect of the independent variable on the dependent. Every experiment has a controlling variable, and it is necessary to not change it, or the results of the experiment won't be valid Controlled variable specification is a part of a study design. They are the entities that could vary, but are kept constant to prevent their influence on the effect of the independent variable on the dependent. controlled variable study design ready for release