On Thu, 24 Mar 2011, Cecil Westerhof wrote:

> When using \startitemize … \stopitemize there is no indent for the first
> paragraph when using \head, but there is when using \item. How can I make
> that by \item the first paragraph also has no indentation?

See 
http://wiki.contextgarden.net/Indentation#Setting_up_indentation_inside_environments

What you need is

\setupindenting[big,yes]
\setupitemize[1][indenting=next]

\starttext
\startitemize
   \item \input knuth
\stopitemize
\stoptext

Aditya