Methodological Limitations

On a methodological level, this research project has encountered two main limitations. The first one lies in the fact that the selection of the samples studied potentially led to biased responses. Some respondents might have an initial interest in water conservation. Responses from these individuals demonstrate more pro-environmental attitudes than responses from more neutral respondents, e.g. respondents to the Ask Cardiff survey. Thus, most of the participants to this study might not be representative of the global population. The second limitation is related to the fact that attitudes, knowledge, habits and beliefs were self-reported by the participants. Their assessment relies on individuals’ perceptions and might therefore be biased.

8.5.1. Possible Bias due to the Self-Selection Sampling Method

Due to practical considerations, the author decided to use a non-probability sampling technique known as the self-selection sampling method in the context of this study. The surveys and the water consultation were conducted in agreement with partners to the project. These partners contacted the participants, distributed the online surveys and conducted the water consultation, in line with the questionnaires designed by the author. After being contacted, respondents to the surveys all volunteered to participate in the study. Respondents to the ‘Ask Cardiff’ survey were also people who volunteered to take part in the annual survey. Emails containing the link to this survey were sent to a random sample of Cardiff inhabitants. These persons then had the choice to answer or not answer the questionnaire and, in that sense, were self-selected. Respondents to the WISDOM questionnaire had agreed to been consulted again in

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the ‘Ask Cardiff’ survey (Appendix A). Respondents to the water consultation had all replied to the letter sent by Welsh Water calling for volunteers. Finally, when responding to the online questionnaire, participants to the trial phase in the office setting had to provide their email addresses if they wanted to take part in the focus group. Concerning the water experts, another non-probability sampling method was used: the snowball sampling method. A number of water experts were contacted and asked to send the online questionnaire to other experts they knew. The author believes that this lack of probability sampling can therefore limit the generalisation of the results obtained from the surveys. However, these non-probability sampling procedures is often used in qualitative research [413], [449], [450]. The potential limitations affecting the quantitative data obtained from the surveys do not affect the qualitative data obtained from the focus group and structured interviews. Indeed, this data does not intend to be representative but aims at providing a more in-depth understanding of the use of the interface [413], [432].

The self-sampling method used implies that there can be a self-selection bias. Indeed, while the responses obtained from the surveys are relatively similar, it seems that the responses from the ‘volunteered’ respondents differ from the responses given by the ‘Ask Cardiff’ respondents. Respondents to the WISDOM survey and to the water consultation and participants to the trial phase indeed demonstrate slightly more environmentally-friendly attitudes when it comes to reducing their consumption than Ask Cardiff respondents. This difference is more apparent between the Ask Cardiff respondents and the WISDOM respondents as the questions asked to both samples led to different answers (see Table 8-2). Contrary to the Ask Cardiff respondents, WISDOM respondents are less likely to consider that they are already doing enough to save water. Most of them would like to do more to save water and almost half of them admit that they need tips and advice to reduce their consumption. Respondents to the WISDOM survey also tend to save water primarily for environmental purposes i.e. help the environment and reduce wastage, whereas many respondents to the Ask Cardiff survey save water to reduce bills.

Table 8-2. Differences in answers between respondents to the Ask Cardiff and WISDOM questionnaires.

Ask Cardiff respondents (%) WISDOM respondents (%) Would like to do more to save

water 21.6 67.2

Currently do enough to save

water 67.8 40.9

Save water to help the

environment 60.9 79.8

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The difference between responses from these surveys reflect the positive bias due to the self- selection sampling method used. Indeed, the fact that respondents to the WISDOM survey, to the water consultation and to the trial phase volunteered to be part of the study demonstrates an initial interest in matters related to water consumption. In fact, the average high pro- environmental score of respondents to the water consultation confirm that they adhere to pro- environmental attitudes and beliefs. Regarding the trial phase in an office setting, it is believed that individuals working in this specific office, focused on sustainable engineering, might have an interest in energy or water consumption and suggests that they might be more educated about environmental issues.

Conversely, participants of the Ask Cardiff survey agreed to take part in this survey to express their opinions on their lives in Cardiff. The original intention of this survey was not to question respondents on environmental matters but on the services provided by the city. Therefore, individuals responding to the survey did not know beforehand that it would contained questions related to water consumption. Thus, even though they volunteer to answer the questionnaire, it cannot be asserted that their participation demonstrates an initial interest in environmental or water issues. This explains the lower level of preparedness for change demonstrated by these respondents. This lack of initial interest in water issues also suggests that these individuals represent a more accurate sample of the population. Thus, their responses are likely to echo the beliefs and attitudes of the general public.

However, in spite of this bias, a large majority of respondents to all surveys, consultation and focus group are reluctant to invest in water-saving devices, regardless of their degree of perceived environmental self-identity. By reflecting self-enhancement values, these financial concerns appear to be the main factor limiting individuals’ level of preparedness for change.

8.5.2. Information Bias due to Self-Reporting

According to the author, another limitation of this study lies in the fact that the attitudes, habits and beliefs assessed in the surveys were self-reported by the respondents. This can also be a source of bias related directly to conscious bias from the person providing the data [533]. Indeed, individuals might intentionally or unintentionally influence the information they provide in order to give a good image of themselves [533]. Individuals’ own assessment of their knowledge and awareness of water consumption is subjective and cannot be independently verified. This explains some of discrepancies and contradictions that emerged from the results obtained, as described in section 7.1.4. Indeed, individuals might have mis-estimated their pro- environmental attitudes and knowledge of water issues. Despite demonstrating positive eco- friendly attitudes, respondents’ awareness of the amount of water used within households is

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limited. Likewise, while they report having knowledge of global water and environmental issues, only a minority show evidence of knowing about water issues. According to the literature, mis- estimation also occurs when individuals are asked to assess their own consumption [61], [151], [522]. It is therefore crucial to consider this limitation in order to draw correct conclusions from the results obtained.

In light of the literature described in Chapters 2 and 3, this chapter discussed the results from this research project to fulfil to the four research objectives. Yet, due to practical considerations, the present study had limitations. As recommendations for future work and based the findings from this discussion, the next chapter extends the work conducted in the context of this project by describing an ‘ideal study’ that validate the use of a similar interface in a more adequate setting, based on the relevant literature. While this ideal study do not bring solutions to any of the large-scale contextual barriers aforementioned, i.e. the price of water and the low interaction with water suppliers, implementing the interface differently and in another setting will allow a more in-depth study of the best methods of encouraging behaviour change and will make it possible to evaluate the impact of the interface in households on a longer period of time.

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