Evaluate the reliability of the hardness test. Consider the following: - No known hardness for each material. Prior to the test we did not know the BHN of each material, therefore we didn't have a value to compare our experimental result to - Measuring diameter of indentation. We measured the diameter of the indentation with a ruler (to 1mm accuracy) and a vernier (1/100th mm accuracy). We then calculated the BHN using those results - Should have repeated test several times. We only tested each material once. We could have repeated the test 3 times and taken the mean or median. - Research the actual BHN for each of the materials and compare them to the values from the experiment. - The hardness steel ball which creates the indentation should be 10mm diameter, however it hadn't been calibrated to verify this