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RichConley · 07/20/2006, 01:37 PM

Samala, Fishgrrl, You can run the who has a skimmer/who doesnt have a skimmer for a period of time and thats fine.

"If you use the last set of questions you are going to end up with a single snapshot in time of some keepers of seahorses who may or may not have SH with GBD and may or may not run a skimmer."

Right, the problem is that if you use any longer period of time, (in the past) you start getting into more instances of totally unrelated cases. Pretty much everyone at some point or another is going to get some GBD in a horse.
If you go and ask
"Have you every had GBD in a tank with a skimmer"
"Have you every had GBD in a tank without a skimmer"

You start running into issues of
User A ran his tank for 3 months without a skimmer and had no cases of GBD.

User B ran his tank for 6 years with a skimmer and had one case of GBD. It paints a picture that isnt neccesarily true.

If you're going to use a time frame, it has to be controlled. IE get a whole bunch of people and say "You can't change from having a skimmer or not having one for 6 months" and then collect everyone's data at the end of 6 months.

Trying to take data from someone who had one condition for 6 months and had x problems and someone else who had the other condition for 10 years and had y problems is just too incongruous.

07/20/2006, 01:37 PM	#83
RichConley Registered Member Join Date: Sep 2004 Location: Bostonian in Chicago going to DC Posts: 9,908	Samala, Fishgrrl, You can run the who has a skimmer/who doesnt have a skimmer for a period of time and thats fine. "If you use the last set of questions you are going to end up with a single snapshot in time of some keepers of seahorses who may or may not have SH with GBD and may or may not run a skimmer." Right, the problem is that if you use any longer period of time, (in the past) you start getting into more instances of totally unrelated cases. Pretty much everyone at some point or another is going to get some GBD in a horse. If you go and ask "Have you every had GBD in a tank with a skimmer" "Have you every had GBD in a tank without a skimmer" You start running into issues of User A ran his tank for 3 months without a skimmer and had no cases of GBD. User B ran his tank for 6 years with a skimmer and had one case of GBD. It paints a picture that isnt neccesarily true. If you're going to use a time frame, it has to be controlled. IE get a whole bunch of people and say "You can't change from having a skimmer or not having one for 6 months" and then collect everyone's data at the end of 6 months. Trying to take data from someone who had one condition for 6 months and had x problems and someone else who had the other condition for 10 years and had y problems is just too incongruous. __________________ NO TANKS!!!