What is he difference between a sample and a specimen?

Answer 1

When we want to investigate a certain characteristic or property, we are interested in all members of the group we are investigating. For example lets say we are interested in the heavy metals content of lettuce grown in Co Cork. Every head of lettuce in Cork is the "population". Since it is inefficient to test all lettuce, i.e the entire "population", we take a sample of lettuce, by going to 10 farms and taking 50 heads of lettuce from each farm. The 500 heads of lettuce is our sample. There are several techniques that can be then used to reduce the amount of lettuce even more until we are left with a quantity that can provide us with several specimens that will actually be tested for heavy metals in the relevant equipment (e.g.Atomic Absorption Spectrometer)

Or in the words of the previous expert:

25 cm length of 1 rock sample I collected at one place In that sample I can make a cutting of each 2.5 cm length of 10 rock specimens.