
#1
May1406, 03:03 AM

P: 405

I am working on a primatology project where I need to find a way to measure and plot the (somewhat arbitary) level of variation in behavior (ie from one individual to the next) within a single species and then compare it to another species level of variation. I have entered the data for the select behaviors that will go into this calculation, and I have calculated the mean and standard deviation for one species. But what is considered a high standard of deviation? My conclusion depends on such calculations, so any help is appreciated, even suggestions for other ways to mathematically calculate values of variation and represent them in charts/graphs. I only have data for 45 individuals per species, so I don't think all charts/graphs will be appropriate.
p.s. I haven't taken any real math since high school, so a simple explanation is best. So far, I've read that if you divide the stdev by the mean and get 10% or over, it's considered a high stdev. 



#2
May1406, 03:18 AM

Sci Advisor
HW Helper
P: 3,149

That depends on what you are trying to do. The standard deviation is generally less important than the ZScore  i.e. how many standard deviations a particular measurement is from the mean. If you are attempting to model some process then a "large" standard deviation may indicate some problem with your particular model or data collection methodology.
Standard deviation has meaning only in a particular context. In physics, for example, a large standard deviation in the speed of gas particles means the gas is hot! Also, if you are attempting to model something, you may be more interested in regression or correlation analysis. 



#3
May1406, 05:57 PM

Emeritus
Sci Advisor
PF Gold
P: 11,154

What you can do is compare standard deviations for the behavioral traits of the two species and say that one species shows a larger deviation than the other. By itself, the standard deviation can't be high or low, without a context. The context is usually provided either by theory (which for something like what you are studying, is hugely inadequate) or by more statistics. If most apecies show a deviation of about d in some parameter, and a particular species shows a much larger deviation (3d, say), you might be able to say something about that species (eg : they like to screw around ). Without something else to compare to, there's not much you can say.



Register to reply 
Related Discussions  
Mean Absolute Deviation/Standard Deviation Ratio  Set Theory, Logic, Probability, Statistics  6  
Standard Deviation  Precalculus Mathematics Homework  16  
Changes to Standard Deviation??  Set Theory, Logic, Probability, Statistics  8  
Standard Deviation?  Classical Physics  3  
standard deviation  Set Theory, Logic, Probability, Statistics  4 