Cited reference searching

What are journal impact factors?

A journal impact factor (JIF) is a metric assigned to a journal that is based on the number of times articles published in the journal have been cited within the last few years.  Journals with high impact factors publish articles that are cited more often than journals with lower impact factors. The higher the impact factor the more highly ranked the journal.  It is a metric used to compare journals within a discipline.

What are some issues of concern with cited references and journal impact factors?

• Journal impact factors may play too important a role in hiring and tenure decisions
• Citation rates and impact factors vary widely from field to field and shouldn't be taken at face value, but considered relative to the field of research
• Citation rate may be based on a few prolific authors citing each other, including self -citations
• Citation searching works better for journal articles than books
• Cross-disciplinary research may produce fewer citations.
• Coverage of your particular field in the citation database may be weak
• The research may too recent and not widely known, like emerging fields
• A journal impact factor refers to the journal as a whole, not to individual papers
• The quality of the journal producing the citation
• Some journals also cite articles in editorials, reviews news and other non-research articles to increase the number of cites and thus increase the impact factor of the journal
• There is no guarantee that every paper which ought to be cited will be cited. An un-cited author may be ahead of his peers (e.g. Mendel and his genetics work)

Where do I find the most cited journals in my field and their impact factors?