What is Pair-Wise Test Coverage?

Following is a definition for pair-wise test coverage:“A value from each block for each characteristic must be combined with a value from ever block for each other characteristic” [1]

Let me explain the above definition with an example:

Consider the following characteristics and choices of a shopping cart payment method module:

Payment choices: Credit card, Paypal, Cash, Check

Payment Types: USD, Euros, Rupees

Applying the pair-wise test coverage, we can create 12 tests to cover the above conditions.

Example

Characteristics blocks:
[Credit Card, Paypal, Cash, Check], [USD, Euros, Rupees]

Pair-wise tests:

1. (Credit Card, USD)
2. (Credit Card, Euros)
3. (Credit Card, Rupees)
4. (Paypal, USD)
5. (Paypal, Euros)
6. (Paypal, Rupees)
7. (Cash, USD)
8. (Cash, Euros)
9. (Cash, Rupees)
10. (Check, USD)
11. (Check, Euros)
12. (Check, Rupees)