Boundary value testing is a technique to find whether the application is accepting the expected range of values and rejecting the values which falls out of range.
A user ID text box has to accept alphabet characters ( a-z ) with length of 4 to 10 characters.
BVA is done like this, max value: 10 pass; max-1: 9 pass;
max+1=11 fail ;min=4 pass;min+1=5 pass;min-1=3 fail;
Like wise we check the corner values and come out with a conclusion whether the application is accepting correct range of values.
Equivalence testing is normally used to check the type of the object.
A user ID text box has to accept alphabet characters (a - z) with length of 4 to 10 characters.
In +ve condition we have test the object by giving alphabets. i.e. a-z char only, after that we need to check whether the object accepts the value, it will pass.
In -ve condition we have to test by giving other than alphabets (a-z) i.e. A-Z, 0-9, blank etc, it will fail.