Question: How can we perform testing without expected results?
Answer: Main concept in testing is the expected result.By knowing the expected behaviour of the application or system from SRS and FDS ,we can derive a test case.When executed the derived test case's ,actual result is noted.Any deviation from the expected is considered as a defect.
In Adhoc testing ,there is no need of a test case,but if we want to log a defect ,we should know the expected behaviour of the application or a system.
There is only one possibility for this question according to me.Exploratory testing.
An interactive process of concurrent product exploration, test design, and test execution. The heart of exploratory testing can be stated simply. The outcome of this test influences the design of the next test.Tester will explore the product or application and will note down the expected result and will design a test case and execute the test.