Black-Box Test Techniques
In my prior article, I wrote about test techniques. In this article, I’ll try to share some information about Black-box test techniques.
- Equivalence Partitioning
- Boundary-value Analysis
- Decision Table Testing
- State Transition Testing
- Use Case Testing
Equivalence Partitioning
In the Equivalence Partitioning test technique, the purpose is to separate the entered values according to their ranges and reduce the number of tests to be performed.
For example, a hotel’s check-in hours are between 12:00 and 20:00. It will not be possible to check in before 12 o’clock. If you arrive after 20:00, you can check in by paying an extra fee. After 00:00 check-in isn’t allowed.
There is no need to type them all to test for valid and invalid values. Instead, we can test one value in each value range.
There is no need to type them all to test for valid and invalid values. Instead, we can test one value in each value range.
We can check the specified intervals with 4 or even 3 tests.
Example: 10:00, 15:00, 22:00 (If you want, you can add 01:00)
Boundary-value Analysis
Boundary Value Analysis and Equivalence Partitioning techniques are similar. But Boundary Value Analysis can only be used for denominators consisting of numerical or ordinal values.
Behaviors at the limits of the values determined here are more likely to be wrong than in the Equivalence Partitioning technique.
For example, in order to test the section “No persons under 18 years of age can enter a venue”, we can test a number less than 18 and greater than 18 in the Equivalence Division technique. The probability of encountering an error in these numbers is low. But in Boundary Value Analysis, numbers 17, 18, and 19 are tested. Any sign error “<” or “<=” made here can accept false values as true. If x<=18 is written instead of x<18, persons aged 18 will not be admitted. However, the rule covers those under the age of 18 and the number 18 is not included in this rule.
To explain through the hotel example above. The hours we should test are 11:59, 12:00, 12:01, 19:59, 20:00, 20:01, 23:59, 00:00, 00:01
11:59 and 00:01 indicate invalid values.
Decision Table Testing
You can use this method when you want to determine what happens in which situations. For example, 20% discount will be applied to students and 15% discount to the unemployed in a language course. If a person has both conditions, that person will receive a 25% discount.
State Transition Testing
It is used to test problems that may arise in transition situations. For example, you want to log into a social media account. If you enter your information correctly, it will take you to your profile. However, if you enter your information incorrectly 3 times, it will send you an email and lock your account for 6 hours.
Use Case Testing
The Use Case method is a test form that we write by making the interaction of the system and the user into a scenario. Here we indicate possible situations. To give an example of logging into a social media account. Let’s assume that the user is on the user login screen of the social media application:
I hope this article helped you a little more about black-box testing techniques. In my next article, I will talk about white-box testing techniques.
