The Theme Quotation Index (TQI) is the search machine "Yandex" technology which consists in determination of authority of internet resources with consideration of a quality characteristic as links to them from other sites. TQI is estimated on the specially developed algorithm where particular importance is attached to thematic proximity of a resource and sites referencing it. This indicator is in the first place used for determination of a resource location in the rubrics of the Yandex Catalog. All the sites of reference must be necessarily indexed by Yandex. At the same time only the rounded values which help to approximately orient oneself in authority of partition resources are specified in the corresponding catalog pages.
The TQI value is defined by total «weight» of sites reference. The sites where any individual can put a personal link without privity of an administrator of a resource do not affect TQI. TQI with a value from 10 to even 200 has a scale division value, a pitch 25 equal to 10 to TQI 500 before TQI 1000 — 50, and is further 100.
TQI is calculated for each site known from Yandex, as well as it's one of the major factors influencing a page situation in Yandex search results.