The phrase "a middle tier of" is correct and usable in written English.
It can be used to describe an intermediate level or category within a hierarchy or structure.
Example: "The company has a middle tier of management that oversees the day-to-day operations."
Alternatives: "an intermediate level of" or "a central layer of".
What is clearly evolving in American higher education is a three-tiered system: expensive, elite institutions at the top, a middle tier of less expensive four-year institutions, and a bottom tier of even cheaper community colleges and career schools.
A middle tier of radio hosts helps fill the schedules of AM and FM stations.
Laws said that responsibility for improvements should be handed to a "middle tier" of councils and academy chains backed by successful headteachers.
In place of this "Napoleonic" situation, Mr Hunt proposes a "middle tier" of local oversight, possibly through elected schools commissioners.Doing this without restoring power to local authorities, many of which dislike the new diversity of schools, is tricky.
They would raise the threshold defining big banks for the purposes of the act from $250m to $1 billion and create a middle tier of banks with assets between these limits.
The regional schools commissioners, intended to provide a middle tier of accountability between local schools and Whitehall, were criticised by MPs last month for the confusion and lack of transparency in which they operated.
More controversial is Mortimore's answer to the most pressing policy teaser of how to rebuild a middle tier – the level of decision-making between a school's governing body and the secretary of state.
It is not clear that the education secretary, Michael Gove, sees a case for a middle tier and some of his aides fear it may represent a return of local authority control, which reforms such as academies and free schools were designed to prevent.
Other apps will be grouped into a middle tier, where most of them will fall, and a bottom "unwashed masses" tier for untrustworthy or spammy apps that have little user value.
The accuracy of imputation is improved using a 3-tiered approach, which used an additional middle tier of 50K, compared to 2-tiered approach, especially when the top panel of animals genotyped with 800K SNPs is small.
As part of its schools strategy, Hunt said, Labour was exploring the development of "a middle tier, something that exists between the chair of the board of governors of a school and the secretary of state" which would involve parents and local authorities.
