It´s probably basic question, but I am wondering, what is meant by the term "joint observations"? I´ve seen this for the first time, and in the literature (statistical one) I am using, it´s not wisely interpreted. So, does somebody know, the meaning of it?
The sentences, where it ossurs are:
Turning to bivariate data, the natural support for joint observations on two circular random variables is the unit torus; and a cylinder with unit radius for joint observations on one circular random variable and one linear one.
.....joint observations on two circular random variables, and cylindrical data, corresponding to joint observations on one linear random variable and one circular random variable,
I would say, it should be observations, measured somehow jointly, during some time interval?