August 31, 2018 Yandex has stopped displaying TCI on all resources. He was replaced by IKS – the index of the quality of the site. It will be used in place of the old indicator.
Thematic index of citation, or TCI, Yandex introduced in 1999. This indicator served to determine the credibility of the site based on the number and quality of other sites that refer to it. Since then almost 20 years have passed, and during this time the Internet has changed dramatically: social networks have developed, the number of mobile sites and users has increased, the era of SEO links has passed … The algorithms for ranking sites have also changed a lot: modern search engines take into account the formation of hundreds of different signals. Now the links are far from being the only quality indicator that site owners should be guided by.
Thus, it became obvious the need for a metric that takes into account, in addition to links, other aspects of the quality of the site known to Yandex. Yandex decided to call it ICS – the index of the quality of the site. Under IKS, that is, under the quality of the site, is understood first of all the relevance of the site to the audience. The more users were able to satisfy their needs with the help of the site, the more tasks they solved, the more useful it is. In this case, it is important not just the number of users, but also the degree of their satisfaction, the overall level of trust in the site. Similar principles are used for the basic metric of search quality.
IKS will completely rеplace the TCI. The thematic citation index will no longer be calculated and displayed. Any user or site owner will be able to learn the quality index of his and other sites in Yandex.Webmaster.
When calculating the IRS, all available data is used both about the site and about the business behind it. This data can be obtained both from the Search and from any other Yandex services: for example, Metrics, Maps, Zen and so on. As these data are taken into account, the algorithm for calculating the IRS will change. Now it appears as a beta.

Operator online
27.06.2019, 13:10