At first glance, using the fact that  it would appear that two measurements of  would suffice to be able to obtain an accurate value of :
where  and  are the equilibrium constant values obtained at temperatures  and  respectively. However, the precision of  values obtained in this way is highly dependent on the precision of the measured equilibrium constant values. 
The use of error propagation shows that the error in  will be about 76 kJ/mol times the experimental uncertainty in , or about 110 kJ/mol times the uncertainty in the  values.  Similar considerations apply to the entropy of reaction obtained from .
Notably, when equilibrium constants are measured at three or more temperatures, values of  and  are often obtained by straight-line fitting. The expectation is that the error will be reduced by this procedure, although the assumption that the enthalpy and entropy of reaction are constant may or may not prove to be correct. If there is significant temperature dependence in either or both quantities, it should manifest itself in nonlinear behavior in the Van t'Hoff plot; however, more than three data points would presumably be needed in order to observe this.