in a subclass of the scale-parameter exponential family, we consider the sequential pointestimation of a function of the scale parameter under the loss function given as the sum of the weightedsquared error loss and a linear cost. for a fully sequential sampling scheme, second order expansions areobtained for the expected sample size as well as for the regret of the procedure. the former resear...

We present a general framework for analyzing regret in the online prediction problem. We develop this from sets of linear transformations of strategies. We establish relationships among the varieties of regret and present a class of regret-matching algorithms. Finally we consider algorithms that exhibit the asymptotic no-regret property. Our main results are an analysis of observed regret in ex...

This paper considers the stability of online learning algorithms and its implications for learnability (bounded regret). We introduce a novel quantity called forward regret that intuitively measures how good an online learning algorithm is if it is allowed a one-step look-ahead into the future. We show that given stability, bounded forward regret is equivalent to bounded regret. We also show th...

BACKGROUND Decision-making relies on both analytical and emotional thinking. Cognitive reasoning styles (e.g. maximizing and satisficing tendencies) heavily influence analytical processes, while affective processes are often dependent on regret. The relationship between regret and cognitive reasoning styles has not been well studied in physicians, and is the focus of this paper. METHODS A reg...

BACKGROUND Parental hesitancy for recommended childhood vaccines is a growing public health concern influenced by various factors. This study aimed to explore regret regarding parental decisions to vaccinate their children via possible correlations between anticipated regret, altruism, coping strategies, and parents' attitudes toward the vaccination of their children. METHODS The study was co...

The optimization problem of general utility case is considered for countable state semi-Markov decision processes. The regret-utility function is introduced as a function of two variables, one is a target value and the other is a present value. We consider the expectation of the regret-utility function incured until the reaching time to a given absorbing set. In order to characterize the regret...

BACKGROUND We sought to estimate the extent of decision regret among primary care patients and identify risk factors associated with regret. METHODS Secondary analysis of an observational descriptive study conducted in two Canadian provinces. Unique patient-physician dyads were recruited from 17 primary care clinics and data on patient, physician and consultation characteristics were collecte...

This work deals with four classical prediction settings, namely full information, bandit, label efficient and bandit label efficient as well as four different notions of regret: pseudoregret, expected regret, high probability regret and tracking the best expert regret. We introduce a new forecaster, INF (Implicitly Normalized Forecaster) based on an arbitrary function ψ for which we propose a u...