The phrase "a separate subsample of" is correct and usable in written English.
It can be used when referring to a distinct portion or subset taken from a larger sample for analysis or study.
Example: "In our research, we analyzed a separate subsample of participants to ensure the validity of our findings."
Alternatives: "an independent subset of" or "a distinct sample of".
A 9-factor measurement model was specified on a mixed-gender subsample of the data and then replicated on separate subsamples of female and male veterans.
In sensitivity analyses, we re-estimated the WCD models for two separate subsamples, each of which was restricted to the case control risk sets corresponding to infections that occurred before or after 1 January 1996 (565 and 1382 cases, respectively).
In order to evaluate the validity of recess PA measures, a separate smaller subsample in a different dataset from the Finnish Schools on the Move programme was used to compare these self-reported measures with objectively measured school-time PA.
However, the lower LDs seen for the separate subsamples indicate that the major cause of the level of LD in the common bean is the gene pool structure (Andean versus Mesoamerican).
Results were ten-fold cross-validated, that is, for each patient the sample was divided randomly in 10 subsamples, and for each subsample the model constructed was applied in the remaining nine subsamples, leading to a separate, unbiased estimation of the true classification rate for each patient.
As a validation, we verified accuracy of self-reports by reviewing medical records among a subsample of 239 men who reported bleeding in which we archived blood specimens in 1993 95 for a separate study of genetic risk factors for bleeding.
A separate group of crabs was transferred from 30 ppt to the different salinities or to aquaria without water (terrestrial condition), and subsamples of this group were sampled on day 2 and day 10.
Both factor models were supported by CFA in separate subsamples.
All curve fittings and data transformations were conducted using the software JMP 10 (SAS Institute Inc., Cary, NC) Following overnight group mating, a random subsample of 24 female per cage were separated from males and transferred to a new cage.
