Dear Dave,

I hope you get an answer to your request for a ref.  

I'd be interested to know of it, in case it puts to test the following basic 
principles of measurement.

The problem with an on/off switch is that its state tells you nothing 
about what it takes to flip it.  Furthermore, switches will vary, in useless 
ways.  What 30% of the sample counts as No for "hungry" could be 
what another 26% counts as a Yes for "hungry" - and you'd never 
know unless you have some objective criterion to assess False 
Positives and False Negatives.

However this problem is just as bad for two-category or multiple 
category ratings of "hungry" (or "full" or "like" or "a large amnount"), 
e.g,. from "not at all" to "extremely" / "as much as I can imagine" or 
other verbally vague non-zero anchor(s).  Indeed it's even worse for 
Test Meal Intakes because you don't know if it's loss of epigastric 
pangs, sufficient increase in abominal stretch, lots of firing in the 
vagus, memory of the usual amount of eating I do or knowledge that a 
Health Institute is monitoring them that actually stopped an individual 
from eating more right then.

I'm trying to finish a short review right now on objective ratings and 
subjective intakes.  It all turns on the rater or eater saying something 
exact and independently measurable in principle in making a box in 
the row, by uttering or ringing a number or about the mouthful that they 
refuse.

All the best.  - David.

On 12 Mar 2007 at 15:21, Mela, David wrote:

Dear colleagues,

Doesanyone know a published reference or have directexperience 
relating to the use of"Yes/No" type of hunger question (ie "Are you 
hungry? - Yes/No") in the context of a preload study? For example, to 
see howthe proportion of 'yes' vs 'no' responses might map onto the 
rise/fall of mean values from a category or line scale of hunger? Of 
course the hunger yes/no question might be buried in amongst a lot of 
other yes/nodistractor questions. 

Will greatlyappreciate it if you could send anysuggestionsto me 
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Thanks for any help.

Regards,
Dave

David J Mela PhD 
Senior Scientist 
Unilever Food & Health Research Institute 
PO Box 114 
3130 AC Vlaardingen 
The Netherlands 
Tel +31 10 460-5626 
Fax +31 10 460-5993 
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