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Exam2 Review

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Q1 - Parnas

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Parnas discussed that software is difficult because failures are not independent, functions are not continuous, and interpolation is not useful. Explain what he meant by each of these ideas and how each of these ideas influence the testing of safety-critical software.

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Q2 – van der Meulen

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a.(10 pts) describe his use of equivalence classes. How were they determined?

b. (30 pts) In van der Meulen’s article, he mentioned using the diversity of software programs to improve reliability. Assume that there are 3 programs (Pa, Pb, Pc) that each have failure probabilities of .2 Their

failures sets (A,B,C) overlap such that size of AB(where both Pa and Pb

fail) is .5 of A and .5 of B. Pc is independent of A and/or B. Find the probability of failure of a voting system that uses these 3 programs.

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Q3 Hamlet

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Consider an aquarium that has to make a decision about adding water to their main pool based on the amount of daily rainfall. If they don’t add enough water and there is not adequate rain, the fish die which is very expensive besides being cruel. If they add too much water, it is wasted which costs some money. The inputs are the expected daily rainfall in inches, the water surface area of the pool, and the expected evaporation amount for the next 24 hours. The output of the analysis program is a number that is how much water needs to be added.

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Q3 part A

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•(15 pts) Write Term Rewriting Rules that are true and could be used to change the input values into equivalent sets of input values. Justify that these rules do produce diverse executions.

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Q3 part B

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•(20 pts) Explain how the voting system could be used or modified to improve the fish life expectancy.

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Q3 part C

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•( 15 pts) How could you test Hamlet’s approach sufficiently to justify to your boss the use of this approach.

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Q4a Bertolino

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1.(15 pts) Explain each of the four dreams. Evaluate whether they are practical and whether they are achievable .

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Q4b Bertolino

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(10 pts) Explain Bertolino’s view of the effect of OO on software testing (or why is OO testing not easier).

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Q4c Bertolino

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1.(5 pts) Explain the following diagram. What are the columns, rows, significance of the placements of items, significance of items that span multiple rows/columns.

Remaining Lectures

Thurs, 11/29 – Zachariah paper Tues, 12/4 – Briand, “A Critical Analysis of

Empirical Research in Software Testing” Thurs, 12/6 – finish Briand, review for final Wed, 12/12 2:00-3:50 150 pts

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