Diederik Stapel

Following the scandal, Stapel voluntarily surrendered his doctorate to the University of Amsterdam. In 2013, he reached a settlement with prosecutors providing for 120 hours of community service. The number of retracted publications subsequently continued to rise, reaching at least 58 in 2015.

State of the evidence

Settlement

Attribution

Directly implicated

Reviewers of the book noted that the final chapter reproduced sentences from Raymond Carver and James Joyce without quotation marks in the main text, although the sources were listed separately in the appendices.

State of the evidence

Documented

The Levelt, Noort and Drenth committees concluded that fraud was beyond doubt in 55 publications, with further indications in eleven other, older works. The report also described an insufficiently critical scientific culture that had delayed detection.

Attribution

Directly implicated

The report identified chapters or research based on fraudulent data in ten doctoral theses supervised by Stapel, causing scientific and professional harm to junior researchers.

After reviewing records and conducting interviews, the committees found no evidence that co-authors or doctoral students had participated in the fabrication. The fraud largely relied on Stapel's position as the exclusive provider of data.

Stapel published his autobiography Ontsporing at the same time as the final report. Critics described it as compelling but largely focused on his own emotions and systemic explanations for the fraud.

State of the evidence

Documented

Stapel fabricated or manipulated entire datasets, sometimes claiming that questionnaires had been administered in schools. During the investigation, he was unable to provide contacts because some institutions or data collection exercises had never existed.

Attribution

Directly implicated

Several junior researchers at Tilburg, struck by statistically improbable patterns and results, reported their suspicions. The university promptly launched an investigation that revealed the absence of verifiable source data.

State of the evidence

Documented

Attribution

Directly implicated

Tilburg suspended and then dismissed Stapel following the initial confirmations. He publicly acknowledged fabricating and manipulating data, bringing his institutional academic career to an end.

Attribution

Directly implicated

The interim report quickly concluded that fraud had occurred on a large scale and initiated a systematic review of his entire body of research across the three universities where he had worked.

State of the evidence

Documented

Attribution

Directly implicated

The final report by the Dutch committees established proven fraud from 2004 onwards and indications in publications dating back to 1996, showing that the manipulation was not an isolated episode late in his career.

Attribution

Directly implicated