**3.1 Process of meta-analysis**

Meta-analysis involves a critical examination of multiple accounts of phenomena to review similarities and differences among them (Nijkamp and Pepping 1997-98). The purpose of meta-analysis is to combine findings from separate but largely similar studies. According to some researchers, such studies may be suitable for the application of a variety of analysis techniques (common literature review, formal statistical approaches, etc.) for combining, comparing, selecting or seeking out common elements, relevant results, cumulative properties etc. from a broad set of individual cases (Matarazzo and Nijkamp 1997). Generally, Meta-analysis methods include constant comparison, taxonomic analysis, the reciprocal translation of in vivo concepts, and the use of imported concepts to frame data(Sandelowski and Barroso 2003).

The mata-analysis requires the establishment of an analytic strategy and coding system to categorize data and to interpret findings in relation to predefined research questions. According to Glasmeier and Farrigan (2005) the synthesis process on qualitative research comprises seven steps:

1. Formulation of the research questions;

130 Sociological Landscape – Theories, Realities and Trends

Practice has proved that the classic Meta-analysis in many areas has good applicability, and is considered as "research on research" (Greenaway, Milne et al. 2004). However, this classical method has some weaknesses. The most obvious one is that because this method averages all case studies, and the differences between the various studies are ignored. Therefore the reliability of the analysis results is very susceptible to those flawed researches. In addition, if a single case study has a large sample size, it is possible that the

This method of Meta-analysis improves the classical methods on two aspects. First, the literature becomes more selective, excluding case studies which have defects in the methods and probably mislead the analysis results. Second, the method takes each individual study as the unit of analysis, rather than the results of each individual study. Thus, in essence, each individual research is given the same weight, and the results of the Meta-analysis will not be affected by sample size. However, this method will directly reduce the amount of data involved in the analysis, also the subjectivity of the researchers possibly affects the

The idea of homogeneity testing originated from pattern recognition. Some scholars believe that the traditional statistical test method is not suitable for Meta-analysis. The effective sample size is affected by many factors: the reliability of measurement, sampling limits, reporting errors of data processing, unreported factors, etc. Homogeneity test can effectively distinguish the nuances in different samples. If the homogeneity test is significant for a group of researches, it can be deduced that this group of researches belongs to one category. With this method, people can classified the collected large number of empirical

A variety of Meta-analysis methods has long been used in research field of laboratory medicine, clinical medicine and behavioral science. There are also applications in experimental or quasi-experimental studies in the economic environment (Travisi, Florax et al. 2004). For example, a New Zealand government-funded research built a framework for future implementation of very effective guidelines drawn from the Meta-analysis of 10 government aided community projects (Greenaway, Milne et al. 2004). In recent years, Meta-analysis

Meta-analysis involves a critical examination of multiple accounts of phenomena to review similarities and differences among them (Nijkamp and Pepping 1997-98). The purpose of meta-analysis is to combine findings from separate but largely similar studies. According to some researchers, such studies may be suitable for the application of a variety of analysis techniques (common literature review, formal statistical approaches, etc.) for combining, comparing, selecting or seeking out common elements, relevant results, cumulative properties etc. from a broad set of individual cases (Matarazzo and Nijkamp 1997).

methods began to be used in the environment and climate change related researches.

**3. A meta-analysis framework for exploring the driving causes to** 

studies, figuring out the similar characteristics of each category.

weight given to this study is relatively large, which affects the results of the analysis.

3. Study effect meta-analysis

4. Tests of homogeneity

**vulnerability for coastal hazards** 

**3.1 Process of meta-analysis** 

research.


The process of meta-analysis is not a linear process. 3), 4) and 5) are parallel steps that focus on different aspects of theories, contents and methodologies. Also, the various steps overlap and are circular. The development of the coding system continues throughout all stages, in order to substantiate the process and make sure that all important information is included. In this way, the coding system can be modified, revised and supplemented according to the concrete cases.

Also Matarazzo and Nijkamp (1997) present the meta-study as six different "levels", each of which assumes a particular importance from a methodological point of vview. The levels are named real-world level, study level, pre-meta-analysis level, study selection level, metaanalysis level and implementation level(Matarazzo and Nijkamp 1997).

Combining the different steps and the levels together, meta-analysis is essentially a kind of "mining" or "emerging" of integrated findings. An integrated map of undertaking metaanalysis steps is shown in figure 1.

Fig. 1. The levels and corresponding steps of a meta-analysis

A Meta-Analysis Framework and

objectives of the review.

in Table 1.

way.

**3.2.4 Coding the information** 

process as new information becomes available.

Its Application for Exploring the Driving Causes to Social Vulnerability 133

1. Scoping of the literature: A set of search filters (combinations of search terms) is set up to identify articles relevant to the objectives of the review and undertook scoping searches including searches for existing reviews and primary studies relevant to the

2. Review of questions: The goal of reviewing questions was to determine the true topical similarity of studies. This entailed the comparison of studies on broad surface parameters, including stated research purposes, research questions asked, and the

In order to minimise the likelihood of excluding important information or views (Sherwood 1999), a thorough and comprehensive literature search was undertaken. This required an appropriate and efficient search strategy. In this study we chose to limit our search to coastal hazards defined by Adger, Hughes et al. (2005): coastal floods (storm surges), tsunamis, tidal waves, hurricanes and marine-related infectious diseases (Adger, Hughes et al. 2005). Geographically, we limited our search to eight East and Southeast Asia countries: Laos,

Considering the availability and authenticity, the following electronic databases were used as mining places: JSTOR (www.jstor.org), Sciencedirect (www.sciencedirect.com), Springerlink (www.springerlink.com), Synergy (www.blackwell-synergy.com), Google

For those databases that allowed searches in several languages, the search was limited to documents in English. The time period searched was from 1970 to March 2006. The key words are grouped in three kinds: type of hazards, region and aspects of hazards vulnerability. Through combining the key words, the searching strategy is set up as shown

The collected literatures are sifted further to insure all the articles are related to the aims of this study. Firstly the articles are browsed by titles, but the relevance of a qualitative study is often not clear from its title alone. Second round of sifting is on abstracts. But as (Evans 2002) has noted, the abstracts of qualitative studies vary considerable in the contents, and some are without addressing the research methods used. If a study could not be determined whether should be included in the meta-analysis, a full text reading is required as the last

After getting the collection of sifted literature, the papers are read fully one by one, to abstract the needed information. In order to avoid limiting the approach or excluding relevant literature, we do not apply a pre-defined coding system as in other meta-analysis research, but develop a new system which is flexible enough to be updated throughout the

The coding needs to be done in a way that allows both quantitative and qualitative analysis of the information recorded. Quantitative analysis includes statistical analysis on the numbers and frequencies of certain kinds of information, such as how many times a particular cause of vulnerability is mentioned or how many case studies were conducted in a particular country. Qualitative analysis is aimed at gaining an improved understanding of

Malaysia, Philippines, Thailand and Vietnam, Bangladesh, India, and Indonesia.

(http://scholar.google.com), and Emerald (www.emeraldinsight.com).

outputs produced (Sandelowski, Docherty et al. 1997).
