Yad VaShem's search site for Pages of Testimony has a form for reporting errors,
which until now I have been ignoring. A week or so ago, I reported a series of
errors - mostly transcription errors such as a submitter whose name was
transcribed several different ways, thus blunting the effect of the "other pages
by this same submitter" function.
I am pleased to report that they notified me within just a few days that each of
the reported errors would be corrected. (They only upload corrections every three
months, so it won't show up right away.)
I am reporting this in order to encourage people to a) report errors and b)
revisit your searches >from time to time.