In any scientific study, one sees a situation, forms a hypotheses about that situation, and gathers data that either supports or fails to support that hypothesis. In this respect, the main errors that can occur in a study are sampling (observing the wrong things, or observing a population that is not representative of your observation), or measurement (observing the wrong aspect of your population) (Bernard, 1988). The monitoring techniques presented here have bases in ecologic or transportation monitoring techniques, but the validity of the data gathering techniques have never been established in the literature. When one gathers information about a system, one can only talk about the data that has been gathered, and have confidence that the data gathered are a true representation of what was actually happening in the system, and reasons for that confidence may not be sufficiently established at this point.
A central concern of this thesis is the apparent lack of literature that systematically assesses the relative effectiveness of one (boat traffic) data gathering technique over another. The researchers in the studies cited here have chosen their observation methods with no discussion of the relative effectiveness of their data collection techniques. They have also largely selected their study designs with apparent ignorance of each other's efforts, as only half of them make reference to other boat traffic studies in their reports. Given the difference in study objectives, scales of efforts, and impossibility of replication of these studies, no meaningful comparison can be made directly between their data gathering efforts.