Crainiceanu, Ciprian; Ruppert, David; Claeskens, Gerda; … - In: Biometrika 92 (2005) 1, pp. 91-103
Penalised-spline-based additive models allow a simple mixed model representation where the variance components control departures from linear models. The smoothing parameter is the ratio of the random-coefficient and error variances and tests for linear regression reduce to tests for zero...