Factors that can affect citation rates
There are a number of factors that you should take into consideration, including:
Type of article
Editorials, letters, news items, and meeting abstracts are not included in article counts because they are not generally cited.
Language
Journals publishing in non-English languages or using non-Roman alphabets may be less accessible to researchers worldwide, which can influence their citation patterns and there is a bias in favour of English language material on citation indices.
Refutation
Citation does not automatically imply that a work is of high quality: a work may be heavily cited because lots of other authors are refuting the research findings it contains, for example cold fusion.
Citation bias
Beware of citation bias: people may cite their own work, or work from the journals in which they publish.
Journal history
An impact factor is a measure of average citation impact, not individual citation impact, so an impact factor cannot be used to measure the performance of an individual only that of a journal.
Publication schedule
Time needs to elapse before a meaningful citation analysis can be made, so new journals tend to fare badly.
Format
Not all research work is published and cited in the citation indices: conference proceedings, for example are often poorly covered.
Subject area
Different fields of research publish at different rates: there is generally a much stronger culture of publishing in journals and citing the worth of peers in biomedicine than in engineering.