La diversité de l'offre disponible sous le mot « coaching » est source de confusion pour les clients, les commanditaires et les coachs eux-mêmes. Dans une visée de didactique professionnelle, à partir d'une démarche de recherche socio clinique compréhensive auprès de six cas de coachs, il est montré que le référentiel est davantage un indicateur qu'un organisateur du dit « coaching ». L'absence de conceptualisation du coaching a pour effet l'impossibilité d'un consensus autour d'une définition, d'un référentiel, d'un mode de transmission et de reconnaissance. A partir de quatre organisateurs des métiers de l'humain que sont le rapport au savoir, le rapport aux normes, le rapport aux valeurs et le rapport à l'image du Soi professionnel, les résultats relatifs à l'activité des cas de coachs et à leurs dynamiques identitaires montrent que l'usage du référentiel est un indicateur de leur posture : guidage ou accompagnement. Puisque le mot « coaching » ne dit rien de la posture de celui qui s'en prévaut, la dénomination désignant l'activité d'accompagnement professionnel dans le champ des ressources humaines et ceux qui la pratiquent devra évoluer. Former ces accompagnateurs aux usages contraires du référentiel permettra que s'élaborent le genre du métier, et le style de ces accompagnateurs. / Market supply over the word « coaching » is confusing for customers and partners, and for coaches themselves. With occupational didactics as a line of sight, and a socio-clinical comprehensive approach to study the case of six coaches, this research comes to the conclusion that the reference table appears to be more an indicator than an organizer of what is called « coaching ». Because coaching has not yet been conceptualized, there is no consensus on its definition, nor on a reference table, or on ways of teaching it and it lacks recognition. Using four organizers of human businesses, which are the relationships to knowledge, to norms and standards, to values, and to one's professional self, it is possible to analyse the coaches' activities and identity dynamics. The obtained results show that the use of a reference table is an indicator of the position they adopt: either in a guidance or accompanying position. Since the word « coaching » says nothing about the position adopted by the ones who refer to themselves as coaches, the denomination referring to the professional -accompanying activity in the field of human resources, and to those who undertake it, will have to evolve. Training these accompanying professionals to the contrary usages of the reference table will allow the elaboration of the profession type and the style of these accompanying professionals.

Un référentiel est un document textuel qui cherche à décrire une réalité, souvent complexe, pour qu’elle fasse « référence » et qu’ainsi, elle devienne discutable pour chacun. Il existe des référentiels de diplômes professionnels, des référentiels de compétences utilisés dans l’entreprise, des référentiels d’évaluation, de formation…Cependant, la conception de référentiels pose question sur deux plans : aux problèmes méthodologiques souvent mis en avant, s’ajoutent de vrais enjeux théoriques. La question est de parvenir à saisir, dans un document par nature inerte et généralisant, une activité de travail dynamique et singulière. Cette thèse cherche à montrer, en s’appuyant sur deux interventions avec des masseurs-kinésithérapeutes, conduites avec des méthodologies de clinique de l’activité, comme on peut référentialiser, non les éléments réglés du métier, mais ce qui reste discuté entre professionnels et ainsi obtenir un référentiel qui peut favoriser le développement du métier décrit et seconder les opérateurs dans la reprise en main de leur pouvoir d’agir. / A reference table is a textual document which tries to describe a reality, often complex, so that it made "reference" and so that so, it becomes debatable for each. There are reference tables of vocational degrees, reference tables of skills used in the company, reference tables of evaluation, training …However, the conception of reference tables asks question on two plans: in the often advanced methodological problems, are added real theoretical stakes. The question is to succeed in seizing, in a by nature sluggish and generalizing document, a singular and dynamic working activity.This thesis tries to show, by leaning on two interventions with physiotherapists, led with methodologies of clinic of activity, as we can référentialiser, not elements settled by the job, but what remains controversial between professionals and so to obtain a reference table which can favor the development of the described job.

Approximate query processing is an adequate technique to reduce response times and system load in cases where approximate results suffice. In database literature, sampling has been proposed to evaluate queries approximately by using only a subset of the original data. Unfortunately, most of these methods consider either only certain problems arising due to the use of samples in databases (e.g. data skew) or only join operations involving multiple relations. We describe how well-known sampling techniques dealing with group-by operations can be combined with foreign-key joins such that the join is computed after the generation of the sample. In detail, we show how senate sampling and small group sampling can be combined efficiently with the idea of join synopses. Additionally, we introduce different algorithms which maintain the sample if the underlying data changes. Finally, we prove the superiority of our method to the naive approach in an extensive set of experiments.

Random sampling is a popular technique for providing fast approximate query answers, especially in data warehouse environments. Compared to other types of synopses, random sampling bears the advantage of retaining the dataset’s dimensionality; it also associates probabilistic error bounds with the query results. Most of the available sampling techniques focus on table-level sampling, that is, they produce a sample of only a single database table. Queries that contain joins over multiple tables cannot be answered with such samples because join results on random samples are often small and skewed. On the contrary, schema-level sampling techniques by design support queries containing joins. In this paper, we introduce Linked Bernoulli Synopses, a schema-level sampling scheme based upon the well-known Join Synopses. Both schemes rely on the idea of maintaining foreign-key integrity in the synopses; they are therefore suited to process queries containing arbitrary foreign-key joins. In contrast to Join Synopses, however, Linked Bernoulli Synopses correlate the sampling processes of the different tables in the database so as to minimize the space overhead, without destroying the uniformity of the individual samples. We also discuss how to compute Linked Bernoulli Synopses which maximize the effective sampling fraction for a given memory budget. The computation of the optimum solution is often computationally prohibitive so that approximate solutions are needed. We propose a simple heuristic approach which is fast and seems to produce close-to-optimum results in practice. We conclude the paper with an evaluation of our methods on both synthetic and real-world datasets.