Relationship between "detrimental" and "effective"

Question

A sample IELTS question in the reading section concerns a passage about how dentistry has improved over the last few centuries. The passage includes:

"...for most of the 18th and the beginning of the 19th century...Barber-surgeons didn't just remove teeth, either: they also doled out detrimental advice on how to care for teeth and relieve toothache - suggesting, for instance, that patients pick their gums with the beak of an osprey bird."

The question asks:

Does the following statement reflect the claims of the writer? Answer
YES if the statement reflects the claims of the writer
NO if the statement contradicts the claims of the writer
NOT GIVEN if it is impossible to say what the writer thinks about this.

The statement is:

Picking one's gums with the bill of an osprey was an effective method of pain relief in the 19th century.

The official correct answer is YES. The explanation cites the quoted text above, starting after the colon, with "sooth an aching tooth" substituted for "relieve toothache."

I would have thought the answer would be NO because of the adjective "detrimental" indicating the writer did not think the advice was effective.

Is there a positive relationship between these two adjectives that would make the answer YES?

Answer 1

There is not a relationship between the two words which would make the answer yes without interpretation.

The writer may be assuming that using detrimental forms a contrast between the potential long-term hazards and the short-term relief.

It seems the point of the question is reading comprehension, but it appears to be a poorly posed question. From the text we have

they also doled out detrimental advice on how to care for teeth and relieve toothache - suggesting, for instance, that patients pick their gums with the beak of an osprey bird.

We actually only know that it was detrimental advice, we don't really know how effective it was for pain relief.

Answer 2

The stated answer is simply incorrect. You cannot claim that something is "detrimental" and then assert it was nevertheless effective. That's a flat-out contradiction.

At best, the answer should be NOT GIVEN, since it doesn't say whether picking one's teeth with a bird actually works to relieve pain.

Either "detrimental" is a mistake (and the passage should have used some other word like "salutary"), or you should discard this question as invalid.