our environmental analyses of change in seagrass systems from direct and indirect human perturbations of shallow marine ecosystems must improve if we are to be able to provide credible evidence of change. physical evidence of current and changing condition is critical to support ecological interpretations and management of seagrass habitats as our ability to communicate increases, so does the ease of data storage and transfer. resources on the internet are expanding. on the other hand, costs of physical storage of archived samples increases over time. it is the responsibility of all researchers to stress and promote the archival capability of their associated institutions as well as the ability to share stored data. statistical analyses have become more rigorous and often require careful design choices involving several spatial scales and approaches to data collection. what size of sampling unit? and how many sampling units? are fundamental questions. we give a simple example of how to determine both the size and number of sampling units from estimates of precision. we also discuss the use of power and the need to have a prior knowledge of the effect size we expect to measure prior to the sampling. we also have provided an alternative for all those who do not want to use statistical power, in the form of confidence intervals. confidence intervals allow us to go beyond stating whether or not there has been a statistically significant effect by estimating the size of the effect.