求翻译：但在实际应用中,由于问题的复杂性,人们得到的数据并不一定是精确的、完整的。如果信息系统中某个对象的属性值是未知的或部分已知的,则称这种信息系统是不完备信息系统。是什么意思？

However, in practice, due to complexity of the problem, one gets the data is not necessarily accurate and complete. If the information system in an object's property value is unknown or partially known, describes this kind of information system is incomplete information system.

But in the actual applications, due to the complexity of the issue, it is the data it is not necessarily accurate, and complete. If the information system one of the objects in the attribute value is unknown or partially known, it is called this kind of information system is not complete information

But in the practical application, as a result of the question complexity, the data which the people obtain not necessarily is precise, the integrity.If in the information system some object attribute value is unknown or the part known, then called this kind of information system is the incomplete in

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However, in practice, due to complexity of the problem, one gets the data is not necessarily accurate and complete. If the information system in an object's property value is unknown or partially known, describes this kind of information system is incomplete information system.