Believe Everything You Read?

[ian]

I thought I'd add a little thought on reading evidence and evidence based practice. Now, this hasn't got anything to do with fish keeping, but does go along way into why we should critique evidence properly (mods feel free to move). This is probably taken from the biggest balls up in British and probably the world and the of history medicine and now were starting to see the outcome of this badly critiqued evidence. This is regarding the mmr vaccine. I'm putting this in here, to make people aware that when reading studies, keep an open mind and critique studies properly before believing everything they say...

Please read the link below, it's written in a simplified, which you should all understand.
http/tallguywrites.livejournal.com/148012.html

Tall guy is a medical consultant working in the uk.

 

[Chad]

ADMIN NOTE: The topic of this thread is not autism, vaccines, or the like but rather a discussion of causal relationships vs. correlational relationships. Please do not make this a discussion about vaccines.
 
Along similar lines I remember reading in my Research Methodology text that they once linked polio and ice cream by assigning a causal relationship when they should only have assigned a correlational one.
 
"Example: In the late 1940s, a nationwide study conducted over several years found a high correlation between the incidence rate of new cases of polio among children in a community, and per capita ice cream consumption in the community. (Equivalently, a simple regression model, using ice cream consumption to predict the rate of occurrence of new polio cases, had a high coefficient of determination.) Fortunately for those of us who like ice cream, a re-examination of the data showed that the high values of both variables occurred in communities where the study collected data in the summertime, and the low values of both occurred in communities where the data was collected during the winter. Polio – which we now know to be a communicable viral infection – spreads more easily when children gather in heterogeneous groups in relatively unsanitary conditions, i.e., it spreads more easily during summer vacation than when the children are in school. The high correlation in no way provided evidence that ice cream consumption causes or promotes polio epidemics." But at the time they acted as if it did and encouraged that ice cream be cut out of the diet.
 
http/www.kellogg.northwestern.edu/faculty/weber/emp/_Session_3/Correlation.htm
 
There are many variables to any study so it's important for a researcher or consumer of research not to assign meaning beyond the research. There are many such topics that this has happened with. This is not to say that all research isn't to be trusted but more to say that any conclusions drawn on such research should be met with skepticism and care.

 

[DrRob]

One of the fundamental problems with scientific evidence is the stuff that isn't published.
 
There is an awful lot of work being done that has results that don't benefit the people paying for it to be done. That stuff tends to be swept quietly under the carpet.

 

[ian]

This is very true, the famous piece of literature was also the evedence that ocean spay cranberry juice was good for cycsitis. GPs and the like started to advise there patients to drink ocean spray cranberry juice...the actual research article was funded by the company that owns ocean spray. Here's a little written about it...

http/xenophilius.wordpress.com/2010/12/09/avoid-ocean-spray-cranberry-juice-for-urinary-tract-infection/

 

[eaglesaquarium]

Correlation versus causation is a debate that I've had many a time in the past.  Its a good topic to delve into as a caution for folks who try to read too much into certain studies.
 
 
The beauty for me as a physics teacher is that I can control nearly all the variables that play a role.  The trouble for biologists (and by extension - aquarists) is that there are so many different variables to deal with. 

 

[Chad]

One of the fundamental problems with scientific evidence is the stuff that isn't published.
 
There is an awful lot of work being done that has results that don't benefit the people paying for it to be done. That stuff tends to be swept quietly under the carpet.

 
It is a sad truth that funding can alter outcome. Going back again to my text we discussed how this happens sometimes on purpose but often unconsciously on the part of the scientist or consumer of the research. It's called "confirmation bias".
 
 

Correlation versus causation is a debate that I've had many a time in the past.  Its a good topic to delve into as a caution for folks who try to read too much into certain studies.
 
 
The beauty for me as a physics teacher is that I can control nearly all the variables that play a role.  The trouble for biologists (and by extension - aquarists) is that there are so many different variables to deal with. 

 
I agree. I've mentioned this before on the forum. There are so many factors to decide upon and so many inter-relationships to deal with that it's almost impossible to include them all.

 

[eaglesaquarium]

One of the fundamental problems with scientific evidence is the stuff that isn't published.
 
There is an awful lot of work being done that has results that don't benefit the people paying for it to be done. That stuff tends to be swept quietly under the carpet.

 
There was actually an old story about Edwin Haley and his comet.  He went to Issac Newton for help in dealing with the orbit of the comet he had discovered, and asked for a bit of help regarding its trajectory and period.  He wanted Newton's help in determining this, as his current cohort of folks, including Robert Hooke (of Hooke's Law for springs fame) couldn't figure it out.  When he asked Newton, Newton stated that he had already derived that relationship, but lost it.  (typical of the genius that he was)   Haley needed Newton's work published, to be able to publish his own work, and that was the impetus behind Issac Newton's seminal scientific piece - Philosophiae Naturalis Principia Mathematica. (Natural Philosophy - Principles of Mathematics)

 

[DrRob]

Tall guy is a medical consultant working in the uk.

 
I had him down as a psychiatric unit worker who has since left the profession, but then I don't believe everything I read.