Since their "migration" to an electronic environment, library catalogs have become deceptively easy to use.
They are deceptive in the sense that the researcher must be aware when initiating a search what the catalog contains and if the records are consistent in their format. That is, does the catalog include all the library's records, or only those records entered after the physical card catalog was discontinued, or after the library switched from Dewey classification to LC? Do all records include subject headings? In some catalogs, like the one at the University of Illinois, the online catalog does have records for all the items in the collection. However, millions of those records have no subject headings. Does the library have uncataloged material that might be of importance for your research? Many libraries had a practice of not cataloging newspapers. Thus the researcher will often not find holdings for very important titles like in an online catalog. Until quite recently this was still the case at the University of Illinois, for example. Other practices that can confuse the issue include cataloging part of a serial run, but not the entire title. Thus, an important pre-revolutionary newspaper like Moskovskiia viedomosti might be displayed with only a few years of holdings in a library catalog, when in fact most issues for the 19th century are available.
There is also a long-standing problem with regard to library catalogs that every researcher should keep in mind. It is particularly important in working with serial publications. Many scholarly publications are issued by institutional bodies such as pedagogical institutes, universities, and academies of science. Such publications can be entered into catalogs in various ways.
Thus, the of the Moskovskii Gosudarstvennyi Pedagogicheskii Institut can appear in library catalogs in several ways, depending on what the standard cataloging practices were at the time it was cataloged (and on how well those practices were followed). The text in green below would be entered in the "title" field, the rest of it as an author or corporate author:
The researcher would be counting on cross-referencing to guide him/her through the catalog. Unfortunately, such cross-references are not always available. This example is included here simply to make the point that forms of entry vary widely and when a title is not located under one heading all possibilities must be pursued.