Duration of Studies Capability of ScientistsResearchersReporters Comparability of Methods

106 Wagner et al. 2000a used different tests for different aspects of their study, including the Mann-Whitney U test, two-sample t test, χ 2 test, contingency tables, and the Kruskal-Wallis test. Wagner et al. 2000b used the paired- sample t test, the Wilcoxon paired-sample test signed rank test, two-sample t test, and the Mann-Whitney U test.

4.4 Reliability, quality and usefulness of data information

4.4.1 Duration of Studies

Most of the studies were conducted within a very short period of time, e.g., a few months. Only a few studies lasted for one or two years. While such short studies have provided very useful information, they cannot be used for making long-term predictions.

4.4.2 Capability of ScientistsResearchersReporters

Most studies on coral reefs have been carried out by capable to very capable scientists. Most junior studentsscientists do not have the opportunity to learn SCUBA, snorkelling or marine survey techniques that are required to conduct research on coral reefs. Therefore, most of the work has been done by senior scientist or well- trained students who are capable of good quality output. Qualified scientists have closely supervised any junior scientists involved in coral reef research. Frontier-Tanzania has been making use of non-specialist volunteer researchers throughout Tanzania for the past 10 years. An evaluation by Darwall and Dulvy 1996 of their suitability for coral reef fish surveys showed that their loss of precision in comparison with experienced divers dropped from 13, in their initial dive, to 0.6 after 11 additional dives. It is likely that their precision would have been similar if tested in coral reef habitat surveys. Therefore, it appears that even non-specialists can conduct quality research if they are given sufficient practice. Most review papers and reports on experimental or applied studies have been written by experienced scientists. Thus, most publications are of high quality, standard and reliability.

4.4.3 Comparability of Methods

Some aspects of the repeatabilitycomparability of methods have already been discussed in Section 3.1. In addition, it can be commented that, generally, it is difficult to compare studies done in different places by different scientists since different methods or variations of methods have often been used.

4.4.4 PublicationsGrey Literature