Hi reader , hope you are doing well and with good health Today we are here again to learn something I have experienced. When as a software tester we start our career we got to know testing terms and got confused in most well-known terms for example experimental testing and combinatorial testing testing. Now here I m going to discuss some about combinatorial testing with you. According to the definition "exploratory testing is when tester do not have any document or the use-cases/ scenarios about the system under test" When we are new with testing and our team lead ask to test the system we feel very horrible and scared that maybe I m not finding that bug that is in the system, which he wants me to find out. When I was new with testing many times I use to Google for best practices for exploratory testing but I m unable to find any. But with the passage of time I have observed that there are ways to find out bugs in the system on the available GUI. I have practiced this while doing testing and find out good results. Without making any delay and breaking the silence. Let me share with you.. If you recall the statistics chapter you read in your intermediate book. P= n raise to power r I keep this formula in mind while making combination of fields while testing.. It will be more easy to understand if I explain this with example: The most well known example of Facebook login page, there are only two fields to login. The username and password and a deriving login button, so there are total 3 options to be tested. So if we fit these into the formula then. "N" is the total fields I have which is 2 username, password . And we make 3 fields are there 3 total options a login button n two fields which is is "r". So combinations would be 8. 3(2x2x2=8) which is equal to 8, So permutation would be 8. Username-password-login 0. 0. 0. 0. 0. 1 0. 1. 0 0. 1. 1 1. 0. 0 1. 0. 1 1. 1. 0 1. 1. 1 Note= here 0 would be empty for the field and 1 is the some input. And for the login button 0 is clicking it and 1 is not clicking it.