All in all, I think the best terminology would be
>
> 1. "completely blind" - when the treatment delivered is _completely_ secret
> except for analysis (it needs to remain blind even after analysis if any
> followups are envisaged)
>
> 2. "partially blind" - when the secrecy is not complete e.g. the treater or
> measurer might know.
>
> JOHN BIBBY
>
>
>
>
> On 17 April 2010 15:53, <[log in to unmask]> wrote:
>
>> According to *Managers' Guide to Design and Conduct of Clinical Trials *(Wiley),
>> in a triple-blind experiment, the investigator who makes the reading is not
>> the same as the investigator who administers the treatment.
>>
>> D
>>
>>
>> -------- Original Message --------
>> Subject: [SPAM] Meaning of "Triple blind"? Re: Definition of Single
>> blind?
>> From: John Bibby <[log in to unmask]>
>> Date: Fri, April 16, 2010 3:01 pm
>> To: [log in to unmask]
>>
>> Generally single-blind means the patient is blind, but the doctor/treater
>> is
>> not - see
>> http://en.wikipedia.org/wiki/Single_blind#Single-blind_trials
>>
>>
>> Double blind means that both are
>>
>> I once had to analyse some data and it turned out the patient groups
>> variable was all mixed up. We christened this "triple blind" - even the
>> statistician does not know who is in which group! (In fact, it was
>> noticing
>> some aberrant subgroups that first alerted us to this situation: the
>> pharma
>> people did not know their data was screwy.)
>>
>> JOHN BIBBY
>>
>>
>>
>>
>> On 16 April 2010 19:16, Dr Philip Sedgwick <[log in to unmask]> wrote:
>>
>> > Dear Allstaters
>> >
>> > With respect to clinical trials, I was taught the definition of
>> > single-blind as the assessor was blind to allcoation but tthe patient
>> was
>> > not. The concept I suppose was based on the fact it was always possible
>> to
>> > blind the assessor to allcoation, but not necessarily the patient.
>> Needless
>> > to say I have no reference. I was further taught, like most things with
>> > time, this definition has relaxed and it is possible for the assessor to
>> be
>> > aware of allcoation, but the patient not - still resulting in
>> single-blind
>> > trial.
>> >
>> > Does anyone have thoughts as to an original definition?
>> >
>> > Best wishes
>> >
>> > Philip Sedgwick
>> >
>> > St. George's, University of London
>> > London SW17 0RE
>> >
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>> >
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>> >
>>
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