"extraneous effect" is correct and usable in written English.
You can use it to describe an effect that is not an intended consequence of an action. For example, "The proposed legislation had some extraneous effects, including a large increase in taxes."
His ability to make his own work invisible (he eschews high concepts or extraneous effects) allows the audience to be drawn effortlessly into the world of the play.
What seems to have been going on was that the statistical filter was picking up extraneous effects, often correlated with good economic developments.
Alston is becoming a rarity in modern dance, not simply because his choreography is so profoundly shaped by music but because it relies so little on extraneous effects – elaborate lighting or stage design.
With all the design details on the inside, the bags of Valextra are designed for a man who wants an ergonomic product on the highest level — but resolutely no fancy, extraneous effects.
A number of transition measurements have also provided good control of extraneous effects, and several of these measurements are compared in detail.
The high sensitivity of this index to various extraneous effects such as canopy structure, and the view observer geometry has so far prevented its use at landscape and global scales.
This may be due to (a) the fact that a large proportion of the beam scattered from a thick target consists of electrons which have undergone more than one collision, (b) the insufficiency of the theoretical model, (c) the inclusion of extraneous effects in the experimental results" (pp. 566 67).
The findings of this study suggest that algorithms used to separate physiological from extraneous effects in PRI reflectance may be more broadly applicable and portable across these two climatically and structurally different biome types, when the differences in canopy structure are known.
Finally yet importantly, extraneous effects of task order of the two combined tasks (B3 & B4, B6 & B7) were counterbalanced by two means.
These assays were also performed by treating glp-1 nematodes with glp-1 RNAi to serve as a control for any extraneous effects of the RNAi treatment; we observed no difference in survival on either E. coli or C. neoformans between glp-1 mutants treated with glp-1 RNAi or those treated with vector control (data not shown).
