emaidel was right about the Hi-Fi Tuning fuses

[Feanor]

Apparently, you do not know what a DBT is or you wouldn't have asked that question. Hint: it is impossible unless you introduce spurious black boxes into the equation with contacts that would completely mask the results. Great idea! My conclusions are based upon experience, not arm chair speculation.
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rw

Not necessarily 'black boxes'. To be a valid DBT it is sufficient that the person who switchs the leads and records which component is used in which trial, be out contact with the test subjects (evaluators) thoughout the experiment.