# How to qualitatively describe distribution shapes

I have a distribution which looks a bit binomial, though with a cutoff, i.e.:

$P(x) = 0$ if $x \le 0$, rises to a bell-shaped peak at around $x=0.2%$, appears to tail off exponentially until an abrubt cut such that $P(x)=0$ if $x>1$.

I don't want to make any claim as to what kind of distribution this is, as the mechanism behind it is too complex to analyze. Are there some adjectives that formally describe its shape though? A word that means "a bit binomial-looking"?

• the truncated binomial? Sep 27 '13 at 10:53
• If $P(x) = 0$ for $x\le 0$ and $x>1$ then you only have support between 0 and 1? That doesn't look at all like a binomial? Binomial is a discrete distribution on positive integers so wouldn't "have a peak at 0.2". Perhaps a beta distribution would be a good match to what you are seeing? Sep 27 '13 at 11:26
• @Sideshow Bob: Maybe something like a right truncated gamma distribution? Sep 27 '13 at 12:24
• From this description--which is fine--there is no basis whatsoever to use terms like "binomial" or "beta" or "gamma" to describe the distribution. (The first two conflict with at least one element of the description, anyway.) Some general terms to research in this context include "truncated," "unimodal," and (positively) "skewed."
– whuber
Sep 27 '13 at 13:24