Posted by Katie on .
how do i tell the difference between a binomial distribution and a poisson distribution?

Math 
PsyDAG,
Since this is not my area of expertise, I searched Google under the key words "binomial poisson distribution" to get these possible sources:
http://en.wikipedia.org/wiki/Poisson_distribution
http://en.wikipedia.org/wiki/Binomial_distribution
http://74.125.95.132/search?q=cache:MlyzPAp9dZgJ:webche.ent.ohiou.edu/che408/Distributions_notes.ppt+binomial+poisson+distribution&cd=4&hl=en&ct=clnk&gl=us&client=safari
http://www.stats.gla.ac.uk/steps/glossary/probability_distributions.html
http://www.graphpad.com/quickcalcs/probability1.cfm
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
I hope this helps. If not, continue the search. Thanks for asking.