1st Descriptive Programming is all about identifying an object

uniquely.

descriptive programming in QTP means whenever qtp facing

dificulty with obj identification then we will go with

regular exp or desc prog it means identifying obj unique

prop from the script itself.ex:vbwindow("").vbedit

("attached text:=username").set cdbjd

2nd answer

without using the objectrepository, and by using the

objectspy we will write the DESCRIPTIVE programming .when

ever we will go to DESCRIPTIVE programming :-

(1).when ever objects are dynamicaly changing.

(2).when ever QTP is not going to recognise the objects.

(3).when ever objectrepository size is huge automatically QTP

wil get down slow.

(4).when ever not yet develop the build then only we will use

DESCRIPTIVE programming .

without using object repository and writing the script 
using properties of objects is the descriptive programming.
by using this programming we can write the sscript at the 
time of design itself.no need to wait for completion of 
code and we can save the memory of object 
repository,because the repository stores properties of 
every objects at each occurence.due to this there may be 
slow down of tool performance.we should have one project 
experiance for writing the script at design phase.
if any queries call me at 
9293739871 
Anand