guys as a Test Engineer one should know about this its very
basic, but  I  am surprised that none of you people are gave
answer for this

so here we go;

principles of testing are:---->

* A necessary part of a test case is a definition of the
expected output or result.
 
*	A programmer should avoid attempting to test his or own
program.
 
*	A programming organization should not test its own programs.
 
*	Thoroughly inspect the results of each test.
 
*	Test cases must be written for invalid and unexpected, as
well as valid and expected, input conditions.
 
*	Examining a program to see if it does not do what it is
supposed to do is only half of the battle. The other half is
seeing whether the program does what it is not supposed to do.
 
*	Avoid throw-away test cases unless the program is truly a
throw-away program.
 
*	Do not plan a testing effort under the tacit assumption
that no errors will be found.
 
*	The probability of the existence of more errors in a
section of a program is proportional to the number of errors
already found in that sect


                       cheers       

                       ravibyndur@yahoo.com

Tester must have communication skills means when we write 
about a bug it should be understandable to any one without 
seeing the application and
tester must have negative thinking
tester must have knowledge on system(key board shorcuts 
etc..)

Ya Ravi U r absolutly Write.

One more thing I want to add.

Tester suppose to have good subject or domain knowledge to 
destruct system.

Tester should write test cases in good understandable 
manner.

Suyog SwamiKattampalli
Watershed Tech.,Pune