How do search engines judge whether an article is original or not?

The article is original, the search engine should also be unable to make the absolute correct judgment from the technical, even roughly correct also can't, innumerable stationmaster painstakingly original article often row in many rubbish blog's reprint even after collecting. So far, I think the search engine to determine whether the original standards have been used in the following: The article included time, the link on the site, the weight of the site.

Article contains time: Your article is a decade ago, I have an identical article ten years after the collection, of course, your article is original. But if the time span is shorter, it is difficult to judge, because the high weight of the blog included faster, my article five days ago published the results have not included, the results you reprinted my article after a few minutes, if the search engine that your article is original and my plagiarism, then I am not too unjust?

Links on the site: this should be the most important point to judge the original standard. If your article at the end of a sentence: the article reproduced in a certain SEO blog, or some keywords on the site have links to the keyword link, then judge your article is reproduced the blog should be more accurate. Because if you link to the article's page judgment or relatively accurate, if the link to the station domain name is still difficult to judge. Can not you article link to his blog results he reprinted your articles are search engines think is original it?

The weight of the site: This SEO people should be more able to understand a little. Search engines think that a high weight, high PR blog articles are more likely to be original.

In fact, there is a standard to determine whether the article is original, that is, to view the creation time of the page. For example, your article is the page was created last year, I was created this year, and the article is the same content, so I am the ten reprint you. If you do not understand, just think about our common Word, Excel bar, is not often see their last modification time? We also often use the change time to arrange. Believe that this record to modify the timing of the technology for Baidu and Google is definitely not a problem, this technical problem should be any programmer can solve it? Do not know now Baidu and Google have not used this technology. Of course, the technology is flawed, if my article is original, then I may change frequently, then my article's last modification time may be compared to reprint my article late, this search engine can record the same article all changes the time to solve, this technology is also very easy to achieve. But there are two more questions: first, how much work does that mean? Baidu, Google index is not a computer on the things, nor is it a website thing, but hundreds of millions of of the page, record the time of the page changes do not know in the workload and the search Engine server response ability means how the pressure; On the other hand even if the page is judged to be the first to create, but if the webmaster to the first page to create the original content deleted replaced by others to reprint the article, this How to judge Ah?

Written so much, you can see each of the methods have advantages and disadvantages, search engines should also particularly want to make the right judgments, but not to mention the technical issues, it is enough to judge the standard is maddening. After all, search engines can only be based on People's command to run, if we can not give the absolute right to determine the standard, then the search engine is unable to solve the problem ...