The phrase "an uncontrolled variable" is correct and usable in written English.
It is typically used in scientific or research contexts to refer to a variable that is not being controlled or manipulated in an experiment.
Example: "In this study, we found that an uncontrolled variable could significantly affect the results, leading to potential inaccuracies."
Alternatives: "a confounding variable" or "an extraneous variable".
The administration of propranolol enabled the study but introduces an uncontrolled variable.
Every variable from pressure, temperature, fluid type, and well depth to logistics and metocean conditions requires control; an uncontrolled variable represents risk to the successful outcome of the well test.
The primary explanatory variable of interest, message rate, is an uncontrolled variable.
Without the LD group as a control, this kind of change attributable to an uncontrolled variable would have been impossible to distinguish from the effect of an endogenous timer controlling the response to photoperiod.
The lack of balancing with respect to exposure is an inherent limitation due to the fact that clinical trials are typically controlled with respect to dose, whereas exposure is an uncontrolled variable.
Although the care needs of the residents represented an uncontrolled variable in what was a natural setting, it appeared that a PCW's workload looking after residents and meeting their care needs was high in both nursing homes.
The fact that the change occurred in LD controls as well as experimental groups implicates either a systematic change in measurement methodology of soft testes or a change in some uncontrolled variable.
The uncontrolled variable in these inventory-based calculations, however, is climate change.
We perform these tests at three different temperatures (15°C, 25°C, and 35°C), with uncontrolled, variable, but high humidity (Table S2).
Another possibility is that the specimens used by Ilia et al (2002) [ 6] were different in terms of some other significant uncontrolled variable.
One caveat for the interpretation of our findings is that we only studied males, to avoid compromising our result with the additional uncontrolled variable of the sexual dimorphism in neural bases of spatial navigation (Gron et al., 2000; see Maguire et al., 1999 and Driscoll et al., 2005 for reviews).
