fragmentation in a segment type table

Dear friends,

I will do re-org and also shrink by pulling the fragmented tables either from schema level or database level.

suppose if i give one table and say if I ask you to find out whether this table got fragmented or not? what should I do.

-->if i analyze table "table_name" validate structure <--this will help to find out the corruption is there or not.

-->As per me I think i need to use the segment adviso,but I dont know how to use it.Please  give me the steps.Thanks.

Das