Decision tree practice
Follow decision trees to their outcomes, count paths, and design the smallest set of tests that reaches every outcome.
Tip: when you design tests, fill in only the conditions along each path; the rest can stay empty.
The idea in a minute
A decision tree shows a sequence of yes/no decisions leading to outcomes. Each path from the top to an outcome is one scenario you can turn into a test. A decision tree is not a separate technique in the CTFL 4.0 syllabus, but reading and testing one builds the same thinking you need for decision tables and for decision and branch coverage in white-box testing: every decision outcome (Yes and No) should be exercised by at least one test.
In a tree, every outcome is reached by exactly one path, so the number of paths equals the number of outcome boxes. That is also the fewest tests that exercise every branch.
How to work a problem
Always start at the top and follow one answer at a time. Only the decisions on your path matter.
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