The phrase "a more variable response" is correct and usable in written English.
It can be used when discussing the variability or differences in responses to a particular stimulus or situation.
Example: "The experiment showed a more variable response among participants when exposed to different conditions."
Alternatives: "a more diverse reaction" or "a more fluctuating answer".
The tested analytes included semi-volatile species which exhibited a more variable response on the aerosol detectors.
However, the larval locomotion defect showed a more variable response (Fig. 2C).
In contrast, the tolerant S. pennellii accession had a more variable response to salinity.
Such transient changes cause fluctuations in the temporal dynamics of the corresponding brain signal; networks with more potential configurations elicit a more variable response.
However, the children diagnosed with ADHD showed a lower accuracy score as well as a more variable response pattern (i.e. a higher SE of RT) than the other groups.
Explants cultured in media containing 2,4-D rather than NAA gave a more variable response by forming both shoots and PLBs with maximum PLB production occurring at a concentration (30 µM) that inhibited shoot production completely.
Similarly, the up-regulation of HO-1 protein following activation of PKCε was inhibited by the CREB1 pooled oligonucleotides, with a less marked and more variable response seen with the single oligonucleotide.
T → A rods have much longer and dramatically more variable responses, which exhibit a characteristic plateau followed by an abrupt recovery; variability in the duration of this plateau suggests that a single step dominates the time course of desensitization of T → A rhodopsin.
Postprandial insulin had a more variable treatment response.
Similar, although more variable, responses were observed with von Frey filaments.
As noted above, the questions varied enough that we can see that different types of questions have much more variable responses.
