“…An appropriate stochastic model will be stated in Sect. 3 which was used in Freise et al (2019) and goes back to Lai and Wei (1982), Lai (1994), andChen et al (1999). In particular, the generated sequence x i , i ∈ N, and the observed responses y i , are viewed as values of random variables X i , i ∈ N, and Y i , i ∈ N, respectively, following a stochastic model which we call an 'adaptive regression model'.…”