Numerous factual errors have been discovered in a University of London study guide used by students for the past six years.
A Trinidad-based tutor who lectures students sitting the university's external degree in geography said he had been forced to spend "many extra hours" trying to rectify "hundreds of stunning errors of fact" in the soil science study guide.
Peter Vine of the Institute of Tertiary Tutors in San Fernando, Trinidad, said that students preparing to sit the exam remain confused and unsure whether they would be penalised for answering correctly but contrary to the guide.
A spokesman for the University of London's external degree programmes said this week that the university would send a correction to students and would revise the guide next year.
Dr Vine, who has a PhD in soil science, wrote to the external programme office last September explaining that he had found many mistakes in the 1997 edition, which is still in use.
Mistakes range from incorrect chemical formulae for certain minerals to the mistaken reporting of key academic theories. In one case the word "organic" is used instead of "inorganic".
A British-based expert consulted by The THES said: "Much of it is inaccurate due to typographical errors and some of it is just plain wrong.
Some of it is serious, but the majority is just poor interpretation or careless or thoughtless wording. The more serious errors could translate into mistakes in the real world through application of incorrect principles. I'm shocked that such a careless document has been in circulation for so long."
The London University spokesman said that the guide's author and the external assessor found that the "serious mistakes" Dr Vine referred to "are not so much factual errors as a matter of academic interpretation".