what are the blackbox testing techniques

Blackbox Testing Techniques : 

Blackbox testing techniques are useful to write Optimal cases for responsible modules functional testing in current sprint or s/w. Blackbox testing techniques are also called as closedbox testing techniques or functional testing techniques.They are

Boundary Value analysis : This technique is useful to write testcases related to size or range of input and output fields.

Equivalence classes Partitions (ECP) : This technique is useful to write Test Cases related type of Input and Output fields.

Decission Table (DT) : This Technique is useful to write test cases related to mapping in between inputs and outputs.

Orthogonal Arrays (OA): This techniqueis useful to remove repeated test cases.

State transition flow (STF) : This Technique is useful to write test cases in Order w.r.t functionality.

Error guessing: This Technique is useful to identify defects in upcomming sprints depends on past experience.