"uneven achievement" is correct and usable in written English.
You can use it to refer to an individual's or group's results which are not consistent or which vary from one area to another. For example: "Despite his uneven achievement in math, the student was still able to pass the course."
Steinbeck's career, marked by uneven achievements, began with a historical novel, Cup of Gold (1929), in which he voiced a distrust of society and glorified the anarchistic individualist typical of the rebellious 1920s.
Instead, they took place last week at the Palisade Preparatory School here, in a school district with a history of financial woes and uneven academic achievement, but one whose standing administrators are hoping to boost by providing a private school approach in a public school setting.
Challenged by such issues as uneven student achievement, cuts in funding and growing mandates, our schools have failed to deliver on the promise of providing a high quality education to every child.
His prose style is eccentric and his achievement uneven.
The passage has been uneven but his achievements unquestionable.
The other gap presents patchy, uneven distribution of the achievements.
The former presents how far Iran is from the goals advocated by MDG; whereas, the other gap presents patchy, uneven distribution of the achievements.
Liszt's achievement remains unusually uneven, ranging from some of the greatest music of the 19th century (the Piano Sonata in B minor, the "Stabat mater dolorosa" from the oratorio "Christus") to some of its greatest drivel ("Grand Galop Chromatique").
The "half empty" view emphasizes the failure to raise children's achievement sufficiently and the uneven quality of programs.
In February, the probation inspectorate reported that their operation was "extremely uneven" with "an unacceptably low level of achievement" which included "very disappointing" drug test results.
Extracting a $41-a-share 41-a-share 41-a-sharehe cable compurchaseld be Katzenberg's crowning achievement, given DreamWorks Animation's uneven pricermance in recent years.
