In this paper we build provably near-optimal, in the minimax sense, estimates of linear forms and, more generally, "N -convex functionals" (an example being the maximum of several fractionallinear functions) of unknown "signal" from indirect noisy observations, the signal assumed to belong to the union of finitely many given convex compact sets. Our main assumption is that the observation scheme in question is good in the sense of [15], the simplest example being the Gaussian scheme where the observation is the sum of linear image of the signal and the standard Gaussian noise. The proposed estimates, same as upper bounds on their worst-case risks, stem from solutions to explicit convex optimization problems, making the estimates "computation-friendly." Immediate examples are affine-fractional functions f (x) = (a T x + a)/(b T x + b) with denominators positive on X , in particular, affine functions (N = 1), and piecewise linear functions like max[a T x + a, min[b T x + b, c T x + c]] (N = 3). A less trivial example is conditional quantile of a discrete distribution (N = 2), see Section 4.2.2 Our main results can be easily extended to the more general case of simple families -families of distributions specified in terms of upper bounds on their moment-generating functions, see [23,22] for details. Restricting the framework to the case of good observation schemes is aimed at streamlining the presentation.• Discrete o.s., where ω t are independent across t realizations of discrete random variable taking values 1, ..., m with probabilities affinely parameterized by x.The problem of (near-)optimal recovery of linear function f (x) on a convex compact set or a finite union of convex sets X has received much attention in the statistical literature (see, e.g., [20,10,12,13,14,11,7,8,9,21]). In particular, D. Donoho proved, see [11], that in the case of Gaussian observation scheme (1) and convex and compact X, the worst-case, over x ∈ X, risk of the minimax optimal affine in observations estimate is within factor 1.2 of the actual minimax risk. 3 Later, in [21], this near-optimality result was extended to other good observation schemes. In [8,9] the minimax affine estimator was used as "working horse" to build the near-optimal estimator of a linear functional over a finite union X of convex compact sets in the Gaussian observation scheme. As compared to the existing results, our contribution here is twofold. First, we pass from Gaussian o.s. to essentially more general good o.s.'s, extending in this respect the results of [8,9]. Second, we relax the requirement of affinity of the function to be recovered to N -convexity of the function. It should be stressed that the actual "common denominator" of the cited contributions and of the present work is the "operational nature" of the results, as opposed to typical results of non-parametric statistics which can be considered as descriptive. The traditional results present near-optimal estimates and their risks in a "closed analytical form," the toll being severe restrictions on...