Playing with molecules

Recent philosophy of science has seen a number of attempts to understand scientific models by looking to theories of fiction. In previous work, I have offered an account of models that draws on Kendall Walton’s ‘make-believe’ theory of art. According to this account, models function as ‘props’ in games of make-believe, like children’s dolls or toy trucks. In this paper, I assess the make-believe view through an empirical study of molecular models. I suggest that the view gains support when we look at the way that these models are used and the attitude that users take towards them. Users’ interaction with molecular models suggests that they do imagine the models to be molecules, in much the same way that children imagine a doll to be a baby. Furthermore, I argue, users of molecular models imagine themselves viewing and manipulating molecules, just as children playing with a doll might imagine themselves looking at a baby or feeding it. Recognising this ‘participation’ in modelling, I suggest, points towards a new account of how models are used to learn about the world, and helps us to understand the value that scientists sometimes place on three-dimensional, physical models over other forms of representation.     

Modelling and representing: An artefactual approach to model-based representation

The recent discussion on scientific representation has focused on models and their relationship to the real world. It has been assumed that models give us knowledge because they represent their supposed real target systems. However, here agreement among philosophers of science has tended to end as they have presented widely different views on how representation should be understood. I will argue that the traditional representational approach is too limiting as regards the epistemic value of modelling given the focus on the relationship between a single model and its supposed target system, and the neglect of the actual representational means with which scientists construct models. I therefore suggest an alternative account of models as epistemic tools. This amounts to regarding them as concrete artefacts that are built by specific representational means and are constrained by their design in such a way that they facilitate the study of certain scientific questions, and learning from them by means of construction and manipulation.     

Generative models: Human embryonic stem cells and multiple modeling relations

Model organisms are at once scientific models and concrete living things. It is widely assumed by philosophers of science that (1) model organisms function much like other kinds of models, and (2) that insofar as their scientific role is distinctive, it is in virtue of representing a wide range of biological species and providing a basis for generalizations about those targets. This paper uses the case of human embryonic stem cells (hESC) to challenge both assumptions. I first argue that hESC can be considered model organisms, analogous to classic examples such as Escherichia coli and Drosophila melanogaster. I then discuss four contrasts between the epistemic role of hESC in practice, and the assumptions about model organisms noted above. These contrasts motivate an alternative view of model organisms as a network of systems related constructively and developmentally to one another. I conclude by relating this result to other accounts of model organisms in recent philosophy of science.     

The birth of classical genetics as the junction of two disciplines: Conceptual change as representational change

The birth of classical genetics in the 1910's was the result of the junction of two modes of analysis, corresponding to two disciplines: Mendelism and cytology. The goal of this paper is to shed some light on the change undergone by the science of heredity at the time, and to emphasize the subtlety of the conceptual articulation of Mendelian and cytological hypotheses within classical genetics. As a way to contribute to understanding how the junction of the two disciplines at play gave birth to a new way of studying heredity, my focus will be on the forms of representation used in genetics research at the time. More particularly, I will study the design and development, by Thomas H. Morgan's group, of the technique of linkage mapping, which embodies the integration of the Mendelian and cytological forms of representation. I will show that the design of this technique resulted in a genuine conceptual change, which should be described as a representational change, rather than merely as the introduction of new hypotheses into genetics.     

Models as interpreters (with a case study from pain science)

Most philosophical accounts of scientific models assume that models represent some aspect, or some theory, of reality. They also assume that interpretation plays only a supporting role. This paper challenges both assumptions. It proposes that models can be used in science to interpret reality. (a) I distinguish these interpretative models from representational ones. They find new meanings in a target system’s behaviour, rather than fit its parts together. They are built through idealisation, abstraction and recontextualisation. (b) To show how interpretative models work, I offer a case study on the scientific controversy over foetal pain. It highlights how pain scientists use conflicting models to interpret the human foetus and its behaviour, and thereby to support opposing claims about whether the foetus can feel pain. (c) I raise a sceptical worry and a methodological challenge for interpretative models. To address the latter, I use my case study to compare how interpretative and representational models ought to be evaluated.     

基于任务驱动的网络教学系统设计

本文从目前教育信息化进程的实际出发,构建了基于任务驱动的网络教学系统的整体构架,采用面向对象技术来设计教学任务。     

关于置换特征标的一个注记

利用有限秩自由R-模V与一个G-集Ω构造出一个G-模VΩ,并给出了由它定义的特征标的计算公式,我们的结果是置换模R[Ω]定义的特征标的一个推广。     

概念在因素空间中的落影表现

研究概念是如何在因素空间中由随机集的落影来表现。首先介绍了因素空间的基本思想，然后讨论概念在因素空间中的表现，最后给出了表现外延的落影表示，以及模糊算子的确定方法。