| When scientific articles are found to contain fabricated or plagiarized data, or to be invalidated by pervasive error, they are customarily withdrawn from the literature by published retractions. The effect of retraction was studied by citation analysis of 53 retracted biomedical articles. Two research questions were investigated: Does publication of a retraction depress the frequency of subsequent citation? and Are post-retraction citations negative, or are retracted papers cited in order to support or substantiate the assumptions or findings of the citing article? The first question was studied by comparing the number of citations that each article received during the two years before retraction to the number of citations received during the two years following retraction. A statistically significant difference was found between the number of pre-retraction citations (495) and the number of post-retraction citations (303). The difference remained statistically significant even after estimating the decline in citation frequency attributable to obsolescence. The second question was studied by citation context analysis of the 303 residual articles that had cited the retracted publications. The portions of the citing articles that referenced the retracted articles were classified by a subject specialist according to the typology of citation contexts developed by Chubin and Moitra. Citation contexts were found to be affirmative to a statistically significant extent. With ninety percent of the citations being affirmative, the retracted articles were cited as though they were still valid. The citing articles, whose authors were evidently unaware of the published retractions, were written in standard scientific languages; generally originated in the United States, Western Europe, or Scandinavia; and were published in relatively prestigious journals. A content analysis of retraction statements indicated that only 68 percent specified the reason for retraction, 45 percent were published prominently in the journal, and 40 percent identified the individual responsible for the error or misconduct. The continued, affirmative use of retracted articles suggests that some retractions are going unheeded, and that invalid information may be perpetuated through citation in subsequent articles. |
