Which term describes wrong values used to test errors?

• A. Abnormal test data
• B. Extreme test data
• C. Boundary test data
• D. Trace table

Answer: (A)

Testing how a program handles invalid or unexpected input relies on abnormal test data. This means using values that don’t fit the normal, valid inputs the program expects—such as letters where numbers are required, values outside the allowed range, or missing data—to see if the program detects the issue and handles it gracefully with proper error messages or validation. Extreme test data pushes inputs to very large or small values but may still be valid, boundary test data checks values at or just beyond limits, and a trace table is a tool for stepping through an algorithm’s execution, not a type of input data. Using abnormal data helps verify input validation and error handling so the program doesn’t crash or behave unpredictably when faced with invalid input.