The use of differing instruments to measure the DV would be an
example of a threat to the internal validity of the study, more
specifically instrumentation. There should be several
references/examples to this on the web and in most books on
experimental designs and/or research methods. Most will likely tie
back to (and hopefully cite) Campbell & Stanley (1963?) book on
experimental design (I might be a year or two off on the date).
Basically, if you are measuring the DV in two different ways pre and
post then you can't be sure that the 2nd measurement is measuring
exactly the same trait with the same degree of accuracy as the first
measure. It's often presented as being changes in the reliability of
the measure or using two different observers. It sounds like someone
on the IRB took a crash course in threats to validity and focused so
much on testing/carryover effects that they missed the issue of
instrumentation. (To be fair though, I admit I've seen some textbooks
that fail to mention instrumentation... so it might not really be the
fault of the IRB member.)
Other people have already expressed my concerns with the actions of
the IRB. But I did want to say that from what you've described, this
sounds like it might be exempt research. I know several professors
that would never even think of going to the IRB before doing
something like this in their class (measuring attitudes before and
after a class activity). Then if something was interesting they'd go
to the IRB asking to use data that was already collected as part of a
routine class assessment/evaluation. One of those situations where
it'd be easier to ask for forgiveness than permission from the IRB...
perhaps some of the other details though might make it more clear as
to why this wouldn't be exempt... and of course, only the IRB can
determine what is exempt from review by the IRB...
- Marc
=============================================
G. Marc Turner, PhD, MEd, Network+, MCP
Senior Lecturer & Technology Coordinator
Department of Psychology
Texas State University-San Marcos
San Marcos, TX 78666
phone: (512)245-2526
email: [EMAIL PROTECTED]
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