Susan, I am certain this is my fault but I don't understand what you are saying here - can you have another try? :) I understand the differene between accuracy and precision, and the different types of precision. What I don't understand is this bit: > >Now, having reviewed quite a bit of evidence on this topic, NO ONE >HAS REALLY TESTED PRECISION except for dependability. Dependability >plagues all assessments. If you assess a baby using any tool >included your eyeballs only once -- you have not really covered the >dependability issue -- be it swallows, diapers, behavior, or weight. >It is dangerous practice not to actively listen to what the mother >is telling you and follow up. > >Embedded in the original article, after four years of contemplating >the fact that the education in mathematics and statistics is so >abysmal that even a peer reviewed journal cannot even spot a GLARING >error such as mistaking what actually was a very poor test of >accuracy for a test of precision -- I found a very telling one line >sentence in the original article. > >The authors THOUGHT they were testing evaporative water loss. >Evaporative water loss is basically sweat loss. They actually did >repeat their measurements of test weighing. They concluded that >evaporative water loss was unimportant. What they actually >conducted was a test of precision. The median and the interquartile >range of the differences between these estimates was ---- get this 1 >g. Now PLEASE tell me how one can conclude that a repeat measure >with only 1 g of difference even with evaporative water loss is >IMPRECISE? By their own study results their repeatability was at >least as good a within 1 g of the original estimate. I have found >repeatability of eyeballing the volume of milk in a bottle to be off >by much much more. thanks! Heather Welford Neil NCT bfc, tutor UK, and sadly, literature and languages graduate (in Italian) and a late comer to science :) -- http://www.heatherwelford.co.uk http://heatherwelford.posterous.com *********************************************** Archives: http://community.lsoft.com/archives/LACTNET.html To reach list owners: [log in to unmask] Mail all list management commands to: [log in to unmask] COMMANDS: 1. To temporarily stop your subscription write in the body of an email: set lactnet nomail 2. To start it again: set lactnet mail 3. To unsubscribe: unsubscribe lactnet 4. To get a comprehensive list of rules and directions: get lactnet welcome