In this note we present calculations of coverage and power for three different methods which could be used to calculate upper limits and/or claim discovery in a GLAST-LAT search fora dark matter line. The methods considered are Profile Likelihood, Bayesian factors and likelihood ratio confidence intervals and the calculations are done considering a simple benchmark model of two uncorrelated Poissonian measurements. Profile likelihood has the best coverage properties, the standard X-2 test the worst. For the power, the situation is vice-versa. In choosing a method one has to consider the false detection rate (1 - coverage) and counterweigh it to the possible achievable power.