Sampling strategy

First, purposive sampling, which refers to a ‘non-probability form of sampling’, has been employed as the sampling strategy.231

That is to say, based on the research questions, samples are selected in a strategic way rather than on a random basis. Based on the nature of a comparative study, sampling must be achieved through two levels: first, two countries of the UK and China have been selected; second, units within the case study have been sampled. In other words, sampling areas and then participants are both elements of the sampling strategy.

A typical form of purposive sampling, namely theoretical sampling, has been employed. This contrasts with generic sampling in that the latter belongs to a fixed sampling strategy or non-sequential sampling, which entails that the sample is established at the outset of the research with no adding to the sample during the process itself, while the former emphasises iteration which entails an ongoing process rather than a fixed plan at the

231 _{Bryman (n 47).}

outset.232

In contrast to generic purposive sampling, theoretical sampling is defined as ‘the process of data collection for generating theory whereby the analyst jointly collects, codes, and analyzes his data and decides what data to collect next and where to find them, in order to develop his theory as it emerges’.233

It entails iterations with an ongoing process rather than a one-off process. Therefore it is typically involved in grounded theory that will be discussed in the section on data analysis later on.

In relation to this research, certain eligible NGOs were selected at the outset. After analysing data and generating categories, more samples were then selected according to the requirement to develop categories. With regard to eligible NGOs, these were environmental NGOs (ENGOs). An ENGO is a non-governmental organisation in the field of environmentalism. In the UK, ENGOs have experienced different phases of development ranging from nature conservation to environmentalism and more radical ecologism.234

The definition of an ENGO has not been considered as a controversial issue in the existing literature. In China however, the definition of an ENGO or even an NGO has received significant attention in the literature due to governmental interventions into these organizations. Thus, there are different ways of defining ENGOs in China according to the existing literature. This research employs the definition by Schwartz that ‘environmental NGOs [are] organizations registered with the government Ministry of Civil Affairs, that receive no state funding, and have no official ties to government beyond the 232 _Ibid. 233 _Ibid. 234 _{Rootes, NGOs in Contemporary Britain: Non-state Actors in Society and Politics since 1945 (n 109). Nature} conservation refers to a movement aiming to conserve natural resources, which is considered by some as a part of the broader environmental movement or environmentalism. See Mark Wilson, ‘The British Environmental Movement: The Development of An Environmental Consciousness and Environmental Activism, 1945-1975’ (Doctoral thesis, University of Northumbria 2014).

necessity of a sponsoring unit’.235

The reason why this research focuses mainly on ENGOs is that geoengineering aiming to tackle climate change is closely related to environment issues, and as a public good, geoengineering is supposed to work in the public interest. In order to ensure the quality of in-depth interviews and obtain effective results from them, staff members with high positions, such as directors, from ENGOs as respondents were sought out where available as they could be expected to know more about geoengineering than other non-environmental NGO employees. This was even more so for interviewing NGOs in China as geoengineering research is considered to be at its initial stages and thus few NGOs have noticed or know about it.

This research seeks to identify two types of ENGO in each country, namely ENGOs that have shown interest in GE and ENGOs that have not shown interest in it. Based on the categorisation of two different ENGOs, this research seeks to identify and compare distinctive reasons why they become involved in GE or not. The sampling method has also been chosen to avoid selection bias236

and to try to include all relevant types of ENGOs. Within the two categories, a certain number of participants were invited for the interviews. Moreover, I added to the sample during the process of interviewing in order to gather enough data for developing variables.

The sample selection was based on two categories among environmental NGOs: environmental NGOs who have shown an interest in GE, and environmental NGOs who

235 _{Schwartz (n 144).}

236 _{Avoiding selection bias means, in this research, not selecting on the dependent variable, which is NGO}

have not been engaged or shown an interest in GE. Therefore, the criteria for this study can be classified as follows: 1) the sample selection will be conducted among ENGOs; 2) the regions of samples will be restricted to the UK and China; 3) the samples will cover both involved and non-involved ENGOs. The sample selection criteria aim to examine why some ENGOs have been engaged in geoengineering while others have not. This is expected to answer the research question why NGOs participate or not in relation to GE. Details of samples will be introduced in the following section.