Some considerations about the shape and size of a string

With reference to the question recently raised about shape and size of a string, quasi-classical states of a bosonic string are defined as the states where the mean values of the position and of the velocity are assigned. For unconstrained systems the easiest way of performing this construction is by means of coherent states. The presence of constraints does not allow this simple treatment, there are however suitable modifications of the coherent states by which states with the required properties can be defined. One example of these constructions is explicitly carried out and discussed