Test data is used to verify that the inputs, processing and outputs are working correctly. As test data is initially developed it can verify that the documented algorithm (pseudocode in the example we are doing) is correct. It helps us understand and even visualize the inputs, processing and outputs of the program.
Inputs: My building is 100 feet long by 40 feet wide and 10 feet in height and I selected paint costing $28.49 per gallon that will cover 250 square feet per gallon. We should verify that the pseudocode is prompting the user for this data.
Processing: Using my solar powered hand held calculator, I can calculate (or predict) the total area would be: (100 x 10 x 2 plus 40 x 10 x 2) or 2,800 sq ft. The total gallons of paint would be: (2800 / 250) or //.2 gallons. But rounded up, I would need twelve (12) gallons of paint. The total cost would be: (28.49 times 12) or $341.88. We should verify that the pseudocode is performing the correct calculations.
Output: Only the signifcant information (number of gallons to buy and the total cost) are displayed for the user to see. We should verify that the appropriate information is being displayed.