Survey on Nam Sang Wai ConservationBack

Research Background

In April 2018, Green Power commissioned Public Opinion Programme of The University of Hong Kong (HKUPOP) to conduct the “Survey on Nam Sang Wai Conservation”. The objective of the survey was to gauge HK public’s opinion towards conservation of natural environment in Nam Sang Wai.

The research instrument used in this study was designed by POP after consulting Green Power. All fieldwork operations, data collection and data analysis were conducted independently by POP without interference from any party. In other words, POP was given full autonomy to design and conduct the survey and it would take full responsibility for all the findings reported herewith.

Research Design

Telephone interviews were conducted by interviewers under close supervision. All data were collected by our interviewers using a Web-based Computer Assisted Telephone Interview (Web-CATI) system invented by the research team which allowed real-time data capture and consolidation. To ensure data quality, on top of on-site supervision, voice recording, screen capturing and camera surveillance were used to monitor the interviewers’ performance.

Telephone numbers are randomly generated using known prefixes assigned to telecommunication services providers under the Numbering Plan provided by the Office of the Communications Authority (OFCA). Invalid numbers are then eliminated according to computer and manual dialing records to produce the final sample.

The target population of this survey was Cantonese-speaking Hong Kong citizens of age 18 or above. For landline sample, when telephone contact was successfully established with a target household, one eligible subject was interviewed. If more than one eligible subject had been available, selection was made using the “next birthday rule” which selected the person who had his/her birthday next. The survey was conducted during the period of April 16 to 19, 2018. A total of 1,003 eligible subjects were successfully interviewed, including 670 landline and 333 mobile samples. The effective response rate of this survey was 57.5%, and the standard sampling error for percentages based on this sample was less than 1.6 percentage points. In other words, the sampling error for all percentages using the total sample was less than plus/minus 3.2 percentage points at 95% confidence level.

To ensure representativeness of the findings, the raw data have been rim-weighted according to figures collected in the 2016 By-census regarding the gender-age distribution of the Hong Kong population and the 2017 educational attainment (highest level attended) distribution and economic activity status distribution obtained from the Census and Statistics Department.