On Almost Interpolation

We obtain some characterizations of almost interpolation configurations of points with respect to finite-dimensional functional spaces. Particularly, a Schoenberg–Whitney type characterization which is valid for any multivariate spline space relative to an arbitrary partition of a domainA⊂^mis presented. As a closely related problem we investigate sectional structure of finite-dimensional spaces of real functions on a topological spaceA. It is shown that under some reasonable restrictions onAany space of this sort may be considered as piecewise almost Chebyshev.