【正文】 s mode of functioning should be revealed to the user. With ?black box? products operation may be very simple because the user is not required to understand anything of how the product actually works However． if something goes wrong, then the user may have no idea how to correct this as he or she will not understand the process behind the way in which the product works On the other hand ?glass box ?products． Where the user is more involved in the process may require more effort to learn. Once mastered． however． The user will be able to understand the workings of the product and may be able to e up with some innovative solutions should a problem occur They have． in a sense, been empowered through having to make the extra effort to learn how to use the product In the first place. In conclusion， the introduction of pleasure in the criteria of usability is essential. It is an element of renewal for a discipline which was for a long while oriented towards suffering and a beneficial return of product ergonomics to the ergonomics of working conditions The creation of a reference for pleasure is thus all the more necessary Models and parameters might then allow us to approach this notion in a scientific way, thus approaching the very question whose plexity adds to the pleasure of its study! 。 it might even go as far as causing an impression of austerity. With such a decoration, the banker will work with greater pleasure feeling more credible in relation to his/her customers thus more at ease, which will in turn make his/her, work easier. Fatigue and pleasure Tired but happy! This is the expression corresponding to a satisfaction which has demanded quite deal of physical or intellectual effort. Here as well, personal investment and pleasure are harmoniously united. To prevent pleasure being replaced by stress, it is, however, most important that the demands on availability of time and mind are strong. The feeling of satisfaction in relation to the result obtained might be related to the effort made to obtain this result. For many people sports give satisfaction by the physical effort made to obtain this result. For many people sports give satisfaction by the physical effort more than the level of performance in itself, the important aspect is to participate. Marathons which have increased in number in cities all over the world is a good example of this. Ethics and pleasure We have placed religious as well as nonreligious considerations in this category, these concern systems of value accepted by the social groups which have multiplied across the modern world. We have observed that usability was badly regarded if it caused social problems such as increasing unemployment The current ecological problems are showing tendencies in this direction and can even lead to active intervention Cleaning and the salvage of waste products are not in themselves pleasurable activities even though the feeling of having respected nature can exist． Progress in ecological problems in ethical terms is both a basic tendency and an element of solution The pleasure of earning money on the stock market might he thwarted by the immoral aspect of the utilization of the funds thus gained This way of thinking has lead to the creation of ethical funds in the USA． Here the investor is assured that his savings are not placed in the support of projects that in his view are immoral． On the contrary． While gaining capital he will feel a pleasure in contributing to stocks that support sustainable development Different religions have decreed rules forbidding certain pleasures like greed and lust， whereas technological progress has destroyed some of the disastrous consequences of these pleasure. The specialized?lowcalorie／health food． Products contribute to the appreciation of good food without creating health problems. Some people feel a certain pleasure in the punishments afflicted to them More monly． and In a rather lay sense a medication that leads to pleasure could be suspected of being inefficient. MANAGING PLEASURE AND DIFFICULTY IN PRODUCT DESIGN We have seen that pleasure in use is not always associated with usability in deed． There are occasions where difficulty in use can increase the pleasurebility of interaction for example by raising the users? sense of selfesteem It is evident that