This paper addresses the problem of using future multivariate observations with missing data to estimate latent variable scores from an existing principal component analysis (PCA) model. This is a critical issue in multivariate statistical process control (MSPC) schemes where the process is continuously interrogated based on an underlying PCA model. We present several methods for estimating the scores of new individuals with missing data: a so-called trimmed score method (TRI), a single-component projection method (SCP), a method of projection to the model plane (PMP), a method based on the iterative imputation of missing data, a method based on the minimization of the squared prediction error (SPE), a conditional mean replacement method (CMR) and various least squared-based methods: one based on a regression on known data (KDR) and the other based on a regression on trimmed scores (TSR). The basis for each method and the expressions for the score estimators, their covariance matrices and the estimation errors are developed. Some of the methods discussed have already been proposed in the literature (SCP, PMP and CMR), some are original (TRI and TSR) and others are shown to be equivalent to methods already developed by other authors: iterative imputation and SPE methods are equivalent to PMP; KDR is equivalent to CMR. These methods can be seen as different ways to impute values for the missing variables. The efficiency of the methods is studied through simulations based on an industrial data set. The KDR method is shown to be statistically superior to the other methods, except the TSR method in which the matrix to be inverted is of a much smaller size.

Purpose In the fertile line of research on consumer value from the services literature, a gap exists between theoretical and empirical knowledge, in particular regarding Holbrook’s conceptual value framework. The purpose of this paper is to find construct validity for a multidimensional value scale based on Holbrook’s proposal. Design/methodology/approach Based on a literature review, a qualitative phase, and consultation with an expert, eight value scales (efficiency, service quality, play, aesthetics, status, esteem, ethics, and escapism as an adaptation of spirituality) are tested on a sample of 585 hotel customers and are further analyzed with simple and partial correlations, multiple regressions, and structural modeling. Findings Following the literature on the merits of Holbrook’s value typology, results are presented in three concatenated phases: validation of Holbrook’s eight value scales corresponding to his eight value types; interrelationships between these value types showing a predominance of the extrinsic-intrinsic and self-other dimensions; and construction of six indices based on the 2×2×2 matrix (self, other, extrinsic, intrinsic, active, and reactive) and a value index as a higher-order representation. The results support Holbrook’s typology, thereby supporting construct validity for the multidimensional scales. Research limitations/implications Implications for further conceptual research on value are presented. Meanwhile, the empirical study is context-specific, i.e. related to a hospitality experience. Originality/value Although Holbrook’s typology has gained widespread attention, to the best of the authors’ knowledge, no previous research has tested all eight value types simultaneously in the same empirical work.

The proportion of patients who defaulted from MDR TB treatment was relatively low. The large proportion of patients who had culture-positive sputum at the time of treatment default underscores the public health importance of minimizing treatment default. Prognosis for patients who defaulted from therapy was poor. Interventions aimed at preventing treatment default may reduce TB-related mortality.

Purpose Within the abundant and not always unanimous body or research on conceptual and methodological approaches to consumer value in services, there are two areas of relative consensus: the multidimensional nature of value (intra-variable approach) and the existence of causal relations with other constructs (inter-variable approach). This work aims to contribute additional knowledge in both areas, with a joint approach in a structural model tested for hospitality services. Design/methodology/approach The study proposes four scales of intrinsic values (entertainment, aesthetics, ethics and spirituality as relaxation), based on Holbrook’s (1999) value typology, and a casual model to be used to measure the relationships between these four values and overall perceived value, satisfaction and loyalty. The model is tested with PLS on a sample of 585 hotel guests on the island of Sardinia (Italy). Findings The psychometric properties of all four value scales, created ad hoc, are tested and approved. Results on the causal model show contrasted links on the intra-variable approach, entertainment, aesthetics and spirituality (measured as relaxation), are positive antecedents of perceived value, while the path ethics-overall value is not confirmed. The value–satisfaction–loyalty chain is fully confirmed, with strong linkages. Research limitations/implications The authors acknowledge the use of a convenience sample, of mainly leisure tourists. Practical implications The implications for managers are derived on the need of considering extra drivers (intrinsic and therefore fully experiential) of satisfaction and loyalty. Originality/value Research on value has been qualified as not univocal and controversial. This study adds knowledge on the use of four less common value types (intrinsic ones) and sheds light on their nature as antecedents of the well-known value–satisfaction–loyalty chain.

If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/ authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. AbstractPurpose -The purpose of this paper is to explore the classical topics of services literature in a tourism experience with a means-end-model on the quality-value-satisfaction-loyalty chain. Within this wide stream of research, this work has a particular interest on value antecedents and on the sense of the link between value and satisfaction.Design/methodology/approach -An overall tourism experience with positive and negative antecedents (benefits and sacrifices experienced) and classical evaluations (perceived value, satisfaction and loyalty as behavioral intention) is analyzed through two competing structural models measured with partial least squares on a sample of 274 students traveling in groups for leisure purposes.Findings -The empirical findings show that: the chain of constructs service quality-perceived value-customer satisfaction-loyalty is once again confirmed in a service setting; affective antecedents (social value, play and aesthetics) are more important determinants of perceived value and satisfaction than cognitive antecedents (efficiency, quality and effort spent); and the model performs better when value is understood as an antecedent of satisfaction than in the opposite case.Research limitations/implications -The findings illustrate how tourism settings are paradigmatically useful for researching perceived value within services because of the differences found between cognitive and affective antecedents. The target chosen (students) and the sampling method used (convenience) need further replication in order to assure the validity of the results.Originality/value -Besides the use of PLS (rather than LISREL), the empirical purpose of measuring with same data a value-satisfaction link and the reverse is interesting for services researchers in order to progress in the debate on the supremacy of one or another.