Introduction orthogonal experiments: the
orthogonal experiment is to study the multiple factors and levels of one test method, which is designed to test the use of orthogonal, alternative comprehensive testing by a small number of tests
in one trial, the the amount of influence the test results is called experimental factors (factor), referred to as factors. Factors can be understood as independent variables during the test, the test results can be seen as a function of factors. During the test, each factor may be in a different state or condition, the state or condition in which the factors, called the level of factors, referred to the horizontal.
For example:
a university communications department a total of two classes, just finished a course, want to "sex", "class" and "achievements" of the three conditions of the query results communication system of this course the distribution of men and women class ratio or the ratio of personnel query:
according to "gender" = "male and female" queries
based on "class" = "class 1, class 2" inquiry
based on "achievement" = "pass, fail" inquiry
in accordance with traditional design - all test
analysis of these test requirements, there are three test element, the test element we call factors, each has two values, which we call level value (i.e. 2).
If an ordinary full test, the following (2 ^ 3 = 8)
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comprehensive test table
when the orthogonal test
the use of orthogonal test design, the number of test cases we get n = 3 * (2 -1) + 1 = 4 (that is, the company (factor * number (the maximum number of horizontal -1) +1)), for a two level factors there are just three L4 (2 ^ 3) orthogonal table can be applied
so with n Matrix for deposit obtained the following four test cases (test type generally orthogonal to the table shown) orthogonal test chart orthogonal design
General experimental design similar to the design including the steps of orthogonal design test cases:
(1) the factors determining
factor here refers to software running software affect the results
in the range (2) or to determine factors set (step 3 this step is to prepare)
ranges factor refers to the range of the input or collection of software and hardware resources are available.
(3) determining the level of each factor
according to the range or set of factors, using equivalence partitioning, boundary value analysis and other software testing techniques, selected equivalence class within the effective range or set of values of each factor invalid equivalence class, exactly equal to, greater than, or just less than the boundary value just like a representative test value.
(4) selecting an orthogonal table
based on the determined factors and levels, select the appropriate orthogonal.
If the number of test cases is not much useful or appropriate orthogonal to adjust the factors and levels.
Constituting orthogonal table:
l number (Runs) line: the number of rows of the orthogonal table, i.e. the number of tests, but also by the number of orthogonal test design method
l number of factors (Factors): Orthogonal the number of columns in the table, i.e., function points to be tested.
l number (Levels) levels: the maximum number of values that can be taken to any single factor, i.e., the function to test point input value
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(Source: ed ed school test software testing)