The talk is base on [1] in which two polymer stretching experiments are compared. 
The outcome of both experiments is a force-extension relation. It is shown that in general 
the two quantities are not equal. In certain limits, however, both force-extension relations coincide. 
To prove this statements, we use a one-dimensional model (developed in [2]) to describe the polymer.

[1] E. Van der Straeten and J. Naudts, A one-dimensional model for theoretical analysis 
of single molecule experiments, arXiv:cond-mat/0601263 
[2] E. Van der Straeten and J. Naudts, A two-parameter random walk with approximate 
exponential probability distribution, arXiv:math-ph/0512077