There is one population of horses. Assume two groups are randomly selected. Every member of each group has the exact same wound given to them.

You want to determine whether applying manuka honey to the wounds affects their size after a period of time. So one group has the wound left untreated, and the other treated with manuka honey.

The question is whether the two groups are independent in the sense that the wound size in the untreated group is independent or dependent on the wound size in the other group.

This will determine whether a paired or unpaired t test will be used.

It seems to me that the wound size from an untreated horse will be independent of the wound size of the treated horse. Yes both horses have a natural level of healing but this would be independent between the horses (they are not cloned pairs).

What I think is that the wound size of the untreated horse could vary in size, but this would not affect the wound size of a treated wound, and vice versa, and hence independent variables. The horses or wounds in the two different groups are not paired.

Thank you.