Introduction
According to Article 1 of the UNESCO Universal Declaration on Cultural Diversity, ‘Cultural Diversity is the common heritage of humanity and should be recognised and affirmed for the benefits for the present and future generations’ (available at the homepage of the UNESCO Youth Forum, 2005). Throughout the last decade much educational discourse has concerned globalisation, communication and information technology, knowledge-based economies, quality of education, and human capital formation and assessment. There has been little debate concerning UNESCO's ‘Learning to Live Together’ (see Rao, Reference RAO2005). There is increasing recognition of the important role that culture plays in the framing and delivering of education and the development of plural, varied and dynamic identities. The acquisition of cultural knowledge from other societies, or multicultural education, is taking place more often and more widely than ever. Many nations celebrate cultural and ethnic diversity as a national strength because it brings together individuals from all academic levels and disciplines, and from diverse educational institutions, organisations and communities. It is now widely recognised that multicultural education requires a holistic approach to schooling that permeates all aspects of the curriculum and all school practices (see Lee, Reference LEE2001; Yeung & Yeung Lee, Reference YEUNG and YEUNG LEE2006; Bergeron, Reference BERGERON2008).
Music has the power to provide people with ways of understanding, maintaining well-being, influencing general self-concepts and promoting communication within the educational community (Campbell, Reference CAMPBELL1993, Reference CAMPBELL2002; Hays, Reference HAYS2005). Music education is thought to promote cultural diversity in multicultural populations, and to widen students' musical repertoire and enable significant musical experiences of diverse cultures (see Fung, Reference FUNG1995; Banks, Reference BANKS1999; Campbell, Reference CAMPBELL1993, Reference CAMPBELL2002; Campbell & Beegle, Reference CAMPBELL and BEEGLE2003). DeNora (Reference DENORA2000) argues that sociological considerations are needed in music education to teach students where they are both musically and socially (also see Stock, Reference STOCK2003; Skelton, Reference SKELTON2004; Green, Reference GREEN2005), and to help them understand music within its particular cultural context (see Palmer, Reference PALMER1992; Jorgensen, Reference JORGENSEN1997; Reimer, Reference REIMER2002; McCann, Reference McCANN2003; Westerlund, Reference WESTERLUND2003; Abril, Reference ABRIL2006). However, no direct study of the music education system of Hong Kong has been found that addresses music education with respect to diverse cultures.
The ways in which education shapes cultural and social dynamics have been well rehearsed in China (for example, see Hayhoe, Reference HAYHOE1984; Cheng et al., Reference CHENG, JIN and GU1999; Law, Reference LAW2002; Bray, Reference BRAY, Min, Yang and Li2003; Qi & Tang, Reference QI and TANG2004; Postiglione, Reference POSTIGLIONE2008). The acquisition of cultural knowledge from other societies, or multicultural education, is taking place more often and more widely than ever. With particular reference to Hong Kong music education, this paper questions the extent to which schools have introduced diverse musical cultures to the curriculum in response to the changing society.
Policy context: Social change, culture and music education in Hong Kong
Hong Kong is located on China's south-eastern coast, incorporating a small portion of the mainland east of the Pearl River, and adjoining the Guangdong Province of the People's Republic of China (PRC). Almost 95% of its 7 million residents are ethnic Cantonese-speaking Chinese, whilst the remaining 5% comprise various nationalities, including Filipinos, Indonesians, British and Indians. Hong Kong has never been a nation-state. As part of the British territories, all policies in Hong Kong between 1842 and 1997 were exclusively administered by the British government. According to Article 18 of, and Annex III to, the Basic Law of the Hong Kong Special Administrative Region (HKSAR) of the PRC, the Nationality Law of the PRC has been applied in the HKSAR from 1 July 1997.
Owing to its open, dynamic economy and socio-political evolution, relationships between music education and society have changed significantly over the last 10 years. Music in Hong Kong is viewed as an intercultural activity framed by Western, traditional Chinese and local Hong Kong cultures. Three local professional orchestras – the Hong Kong Philharmonic Orchestra, the Hong Kong Sinfonietta and the Hong Kong Chinese Orchestra (the only local professional, full-size Chinese orchestra) – regularly perform Western and Chinese classical music, give outreach courses and visit communities and schools. Cantonese opera, which is one of the main categories of Chinese opera, originating in southern China, has also been encouraged to be promoted in schools and the community. The current music curriculum guide also includes Cantonese popular songs for the first time, to help students understand the cultural and historical contexts of this style (Curriculum Development Council, 2003).
In the ‘Greater Chinese union’, China as a united culture would take precedence over Hong Kong as a nation-state. The union would have a common flag and anthem, and a shared traditional Chinese musical culture. The current educational reform includes Chinese culture in arts education (Curriculum Development Council, 2002), whilst national education helps students understand their national identity, and develops their commitment to improving the nation and society (Curriculum Development Council, 2001a, 2001b; also see Ho, Reference HO2007). Singing and listening to folk songs from diverse regions of China (Curriculum Development Council, 2002), and playing Chinese musical instruments are recommended (Curriculum Development Council, 2003).
The government of Hong Kong believes that reformed education should promote multicultural education by fostering global awareness and outlook, and by re-emphasising the quality of students' life experiences (Education Commission, 2000). Tung Chee-Hwa, the first Chief Executive of the HKSAR, said in his 1998 Policy Address, ‘I believe that Hong Kong too has the potential to become, not only a major city within one country, but also the most cosmopolitan city in Asia, enjoying a status similar to that of New York in America and London in Europe’ (Government of Hong Kong Special Administrative Region, 1998: 7).
Global or multicultural education is a relatively new experience for the schools of the HKSAR. Since 1998, global citizenship has become a component of civic education for the junior forms (i.e. Grades 7–9) of secondary schools. Twenty out of 150 lessons in this curriculum are intended to help students appreciate the world's diverse heritage (see Curriculum Development Council, 1998; Law, Reference LAW2004). Citizenship education aims to cultivate Hong Kong youth's ‘positive personal, social, moral and civic values and attitudes’, and their understanding of the relations between Hong Kong and the outside world (Fairbrother, Reference FAIRBROTHER2005: 299). Students should be educated to think about and reflect on different values to their own, their relationships with others, the community, the nation and the world at large (Curriculum Development Council, 2002). They have to be taught to appreciate multicultural diversity in the arts, and are expected to respect and understand the traditions and values of world music (Curriculum Development Council, 2002; Ho & Law, Reference HO and Law2006).
Hong Kong has faced the challenges of political and cultural globalisation since the return of sovereignty from the UK to the PRC. It is within this context that this study proposes cultural diversity to be the key component of its Western-based school music education.
The study
Purpose and research questions
Multiple research methods were employed, including a questionnaire survey to Hong Kong primary and secondary schools, and individual interview surveys with music teachers. There are two main research questions:
(1) How does school music education respond to diverse musical styles in the changing society?
(2) To what extent does the introduction of Chinese music in the curriculum promote a sense of national identity to mainland China in Hong Kong school music education?
Procedures and method
In this study, data were obtained from a questionnaire survey of students in 11 primary and 11 secondary schools in Hong Kong between November and December 2006. Students from primary 3 to secondary 4 (Grade 3 to Grade 10) were selected for the survey sample. Only students from primary three who had sufficient reading and writing abilities to answer the questionnaire in Chinese were selected as the target group. The survey asked students to take 10–15 minutes in school music lessons to respond.
The questionnaire included closed items, multiple choices, and four and five-point Likert-scale questions, which all addressed students' musical background, preferences and attitudes. The students responded to options concerning their musical and non-musical learning in two broad areas, and to requests for general information about music learning at school. First, the subjects were asked for general information concerning their age, gender, grade attended, persons whom students believed to have influenced their musical learning, their interest in music, attendance at concerts and their instrumental learning. Second, students were asked about their attitudes toward music learning in class, including the extent to which they liked school music lessons, whether the teaching contents were practical (from 1 = ‘strongly disagree’ to 5 = ‘strongly agree’), their thoughts on whether they were taught various musical styles, and whether traditional Chinese music and that of other cultures should be emphasised in the curriculum (from 1 = ‘strongly disagree’ to 5 = ‘strongly agree’). The quantitative analyses, such as percentages, standard deviations and means, made use of Microsoft Excel software.
This study also involved qualitative, in-depth interviews with music teachers. On the basis of data obtained from the questionnaire survey, questions were drafted for school music teachers, and invitations to participate in individual interviews were sent to schools. Semi-structured interviews with 20 school music teachers were conducted during January and March 2007. The interviews, which ranged from 50 to 75 minutes, were conducted on a one-to-one basis. Besides some personal background information, they were guided by the following series of open-ended questions:
(1) What do you think is the most important goal for music teaching and learning?
(2) Do you encourage a multicultural approach to school music education?
(3) What are the limitations of a multicultural music education?
(4) Does your school have any programmes on Chinese culture? Do any of these concern music? Does your school have any cultural exchanges with mainland China?
(5) To what extent could the ideology of national identity be integrated into Chinese music teaching?
Notes taken during the interviews were audiotaped. The interview data, which were anonymised, were transcribed manually using Excel software.
Findings
Demographic information about students
Most Hong Kong primary schools provide up to two weekly music lessons for students. Whilst Hong Kong secondary schools run their school music education up to junior secondary level (i.e. compulsory education for Grade 1 to Grade 9, mostly for ages 6 to 15), some only schedule one weekly music lesson up to Grade 10, and most do not plan the general music education in their senior school curriculum. Grade 11 students have to sit the Hong Kong Certificate of Education Examination (HKCEE) at the end of their five-year secondary education
There were 3,243 questionnaires completed and collected from students in Grade 3 to Grade 10 at 11 primary and 11 secondary schools (see Fig. 1).
Fig. 1 Grades attended by students
With regard to age distribution, eleven (0.34%) out of the 3,231 respondents were age seven, 308 (9.53%) were eight, 329 (10.18%) were nine, 435 (13.46%) were ten, 439 (13.59%) were eleven, 515 (15.94%) were twelve, 457 (14.14%) were thirteen, 737 (22.81%) were fourteen and above. Among the valid responses, 1,626 were male (i.e. 50.37%) and 1,602 were female (i.e. 49.63%).
Students were asked to indicate their personal interest in music (from 1 = ‘not at all’ to 4 = ‘much interest’). The average mean was 2.96 (SD = 0.90). Among 3,223 valid answers, 1,373 (42.60%) showed some interest while 998 (30.96%) showed much.
When asked if they had attended any concerts presented in community halls and other cultural centres in the past 12 months, 1,234 (38.05% of 3243) said that they had. Out of those respondents who had attended concerts, 591 (47.89%) had attended only once in the past 12 months, 306 two times, 175 three times, 63 four times, and 99 (8.02%) five times or more. Concerts of Western and Chinese music were the most welcomed by 1,167 (64.26%) and 512 respondents (28.19%) respectively.
There were 1,390 (49.26%) students who believed that the main sources of their musical knowledge were school music teachers; whilst 548 (19.42%) chose private instrumental coaches, and 253 (8.97%) chose parents. This was followed by the mass media with 217 responses (7.69%), school instrumental coaches with 151 (5.35%), internet with 125 (4.43%), friends with 72 (2.55%) and siblings with 62 (2.20%).
Most instrumental learning was taught in school music lessons and extra-curricular activities in schools according to 1,340 (55.93% of the valid answers) and 332 respondents (13.86%) respectively. The five most preferred instruments were recorder, piano, violin, electronic piano and guitar (see Fig. 2).
Fig. 2 Distribution of top five popular instruments among students
In total, 47 different kinds of instruments were taught. These were classified into four different types: Western, Chinese, Japanese and other world music instruments. Out of 4,783 instrumental learners, 4,444 (92.91%) studied Western musical instruments, 317 (6.63%) played Chinese musical instruments, 19 (0.40%) learned world music instruments such as African drums, while only three (0.06%) played a Japanese musical instrument.
Students' perception of music learning at school
Students' attitudes toward music learning in the classroom
Students were asked to express their attitude towards their music learning at school. They were asked to use a five-level tier of agreement (from 1 = ‘strongly disagree’ to 5 = ‘strongly agree’) by which to rate the following three statements: ‘I like school music lessons’, ‘School music lessons are mostly interesting’ and ‘The teaching contents of school music lessons are practical’ (see Table 1). The means of the three statements were 3.47 (SD = 1.17), 3.40 (SD = 1.17) and 3.30 (SD = 1.21) respectively.
Table 1 Attitude toward music learning in classroom
*from 1 = ‘strongly disagree’ to 5 = ‘strongly agree’
Students' attitudes toward various musical cultures
Students were also asked to express their attitude towards the various types of music that they would like to learn in school music lessons: (i) traditional Chinese music, including instruments and singing; (ii) traditional Western music, including instruments and singing; (iii) Chinese folk music; (iv) children songs; (v) popular songs; (vi) jazz; (vii) music of other countries; (viii) Cantonese opera; and (ix) Beijing opera. A five-level tier of agreement (from 1 = ‘no interest’ to 5 = ‘much interest’) was given to rate each musical style. The three preferred musical styles among students were popular songs, traditional Western music and music of other countries; whilst the least preferred ones were Chinese folk songs, Cantonese opera and Beijing opera (see Table 2).
Table 2 Students' attitudes towards certain types of music in school music classes
*1 = no interest, 3 = neutral, 5 = much interest
Students were asked whether traditional Chinese music and that of other cultures should be emphasised in their school music lessons. The respective means of traditional Chinese music, and other musical cultures were 2.89 (SD = 1.22) and 3.37 (SD = 1.28) (from 1 = ‘strongly disagree’ to 5 = ‘strongly agree’). When asked about learning more traditional Chinese music in the school curriculum, 497 students (15.67% of the valid answers) strongly disagreed, 692 (21.82%) disagreed, 1,046 (32.99%) remained neutral, 550 (17.34%) agreed, and 386 (12.17%) strongly agreed. When asked whether they would like to learn other musical cultures besides traditional Chinese and Western, 347 (10.97%) strongly disagreed, 426 (13.47%) disagreed, 845 (26.72%) remained neutral, 804 (25.42%) agreed and 741 (23.43%) strongly agreed.
Music teachers' views of school music education
Twenty music teachers (10 primary and 10 secondary) were involved in the study. Only five secondary school music teachers taught just music. All the other music teachers had to teach at least one or two other subjects including Chinese language, mathematics, religious studies, economics and general knowledge. Nineteen of the 20 music teachers held degrees in music (one primary music teacher held a degree in Chinese Language); whilst 12 held masters degrees in music. Two teachers had taught for less than one year, three for between two and three years, eight between six to ten, and seven for more than ten years (one for 31 years). For ease of presentation, the 20 teachers were numbered from T1 to T20.
Views of the multicultural dimensions of music teaching
When asked about the main goals of music education, most teachers wanted to arouse students' interest in music, develop their creativity and motivate them to participate in musical activities. Only one primary school had an African drumming class, whilst another ran Cantonese opera classes. Most teachers said that the most common extra-curricular activities conducted in schools were choir, and instrumental classes in Western and Chinese music. None of the teachers said that the praxial teaching and learning of diverse musical cultures should be the main goal of school music education and activities outside formal education.
However, when asked about multicultural education in particular, all teachers agreed about introducing a multicultural approach to school music education, and that students should be exposed to different music and different cultures. Most teachers thought that students should learn different kinds of music including Western, Chinese and world music, or even Japanese music, so that students could be exposed to different musical cultures. Students needed to know more about these diverse types of music in order to establish a sense of cultural identity, and to be able to look at things from different angles. One teacher suggested that students should learn different musical instruments from various countries.
However, some teachers pointed out that there were limitations to a multicultural music education. For example, they had only one or two lessons every week/cycle, especially in secondary schools. They also claimed that some students might not be willing to learn other musical cultures, and said that they laughed when topics about other world musics were introduced. Some teachers noted that they themselves hindered pluralist and multicultural education because they were not familiar with all kinds of music, and sometimes the music they taught was based on their educational and musical backgrounds. They said:
T2: . . . I am only familiar with Western and Chinese music. For other music, I only have basic knowledge and teach other world musics superficially. . .
T7: . . . We only have 14 double music lessons during the academic year and we cannot teach as much as we want. We can only present a brief introduction on world music to students . . .
T8: . . . There is not much information about multicultural music materials found in the textbooks. We have to search for the materials and this will certainly hinder the development of multicultural music education.
T11: The Education Bureau only provides us an outline to teach multicultural music. We have to search more resources or grasp the main points from the prescribed outlines. We should update our knowledge on teaching world music before we deliver world music to students . . . We also don't have enough time to introduce so many musical cultures in the music lessons. My teaching on world music is basically superficial . . .
T17: . . . there are not enough materials or information for us to teach world musics . . . we cannot get detailed information and our knowledge of world music is limited.
The promotion of Chinese culture, music and national identity in school education
During Chinese festivals like the Chinese Lunar New Year, the Dragon Boat Festival or the Chinese National Day, schools would promote different activities like lantern riddles, couplet writing, paper-cutting, calligraphy, Chinese painting, an exhibition board showing the development of the Chinese communist map, Chinese handicraft and face painting. When asked if teachers would promote Chinese music at school, the answers of the secondary school teachers seemed to be very negative. Only three said that they ran Chinese instrumental classes. Another six secondary schools only provided some Chinese music learning to students. One secondary teacher even noted that her principal asked her to cut Chinese music lessons from three to one lesson throughout the year because the principal disliked Chinese music. Other reasons for having less or no Chinese music in the school curriculum included ‘not familiar with Chinese music’, ‘students dislike Chinese music’, and ‘time is inadequate to teach Chinese music’. One teacher said that they only played Western music and Japanese music during lunch-hour music appreciation classes. However, Chinese music was considered differently in primary schools, many of which taught Chinese music in music lessons as well in Chinese instrumental classes. The music teacher in School 6 (a primary school with diverse nationalities, including Chinese, Pakistani, Nepalese and Filipino), wanted their students to know more about Chinese culture in order to help the cultural assimilation of foreign students.
Eleven teachers said that they had not had any cultural exchange with mainland China recently. Among those that had, only two said that they had any musical exchange with the mainland, whilst the rest said that music was not the theme of their cultural exchange.
Only six music teachers thought that music education through the teaching of Chinese music could develop a sense of national identity. They said that music like the national anthem and Chinese music generally can appeal to one's emotions, whilst studying the background of music can help to know more about our home country. Other teachers believed that other subjects and the mass media were more suitable for raising issues of national identity. One teacher (T2), who taught ethnically diverse students in English, claimed that they never taught the Chinese national anthem, and that language was a problem for students. Another teacher said that because her students preferred Western classical music, she did not teach traditional Chinese music and other music/songs related to Chinese national identity or patriotism.
Discussion
This discussion focuses on the dynamics and dilemmas of cultural diversity as they relate to music teaching and learning in schools. The focus of this study concerns how to incorporate diverse cultures into a Western-orientated music curriculum; and the second is to find a way to cultivate national identity through music education. Findings suggest that, to different extents, Hong Kong school music education is Westernised, and tends not to focus on multicultural education and Chinese music. There needs to be options offered to refashion students' and teachers' understandings of cultural borders and their positions and relations within different musical cultures.
Firstly, the multicultural understanding of music education, with respect to both instrumental learning and other musical practices, has been narrowed down to styles that might be thought to represent Westernisation. Though students' preference for learning music of other countries was rated third (see Table 2), the mean score was only 2.96 (from 1 = ‘no interest’ to 5 = ‘much interest’). Among instrumental learners in this study, over 90% studied Western musical instruments (see Fig. 2), and only a small portion learned Chinese or other instruments. Students had few opportunities to experience diverse musical cultures in performance. Programmes of Western classical music were well attended by students at public concerts. Despite the positive attitude of music teachers towards multicultural music education, the main reasons for its limited inclusion in the classroom are teacher's insufficient content knowledge and inadequate teaching materials. Recent curriculum reforms (see Curriculum Development Council, 2001a, 2001b, 2002, 2003) recommend that students should learn about music from a variety of genres and cultures. A global awareness of other musical cultures may help students to understand their own Chinese music, and most importantly, to recognise its place within world music.
Despite having only 5% ‘other’ ethnic groups in Hong Kong there has been a paradigm shift during the last decade in the ways in which cultural and social diversity is managed in response to the change of political sovereignty. This shift has had an impact on school music in the sense that its curricula show awareness of issues of living together as a united nation despite cultural and ethnic differences. This awareness was heightened during the International Year for the Culture of Peace in 2000 (UNESCO, 2002). Even if we are not teaching a diverse student population, we still have the responsibility to teach students to celebrate, respect and preserve other nations' cultural heritages through music making and performance. Schools should provide the best in music education, performance experiences for students of all ages, and the willingness and ability to promote diverse music as a valuable aspect of community life. Teachers need to have a clearer understanding of the dynamic process effecting change in musical cultures if they are to overcome their fears about teaching diversity.
Secondly, after 150 years of British colonial rule, there is an urgent need to cultivate students' sense of belonging to HKSAR, as well as to the PRC. The promotion of Chinese music and singing of the PRC anthem are two signs of how nationalisation is emerging to various degrees in Hong Kong music education (Law & Ho, Reference LAW and HO2004). The current educational reform recommends the inclusion of Chinese culture in arts education (Curriculum Development Council, 2002: 48, 101–105), whilst national education is stressed to help students understand their national identity and to develop their commitment to improving the nation and society. Promoting Chinese music and national identity within music education may encounter great resistance because it is a concept borrowed from mainland China. It might be seen as a way of linking Hong Kong's governance closer to that of mainland China, thereby creating a challenge to the framework of one country two systems. In other words, Hong Kong is increasingly becoming a Chinese city, particularly in the alignment of its concepts of governance with those of the Communist Party of China. Nonetheless, many Hong Kong teachers have been sceptical about the political use of music education. An example of this was the schools' reluctance to hold flag-raising ceremonies, and the playing of China's national anthem in the first few years after the handover in 1997 (see Law, Reference LAW2004). This reflects a more deep-seated concern about many teachers and students, who lack interest in teaching and learning Chinese nationalist and other music. On the other hand, the low level of political literacy and low understanding of Chinese music amongst music teachers may be related to their opinions of the relative unimportance of including political and musical values in school music education.
The focus of music teaching in higher education and teacher education in Hong Kong has long been on European classical music. Because of this, music teachers feel confident about teaching Western classical music, and as a result Chinese and other world music in the Hong Kong music curriculum do not receive much attention. While UNESCO (1996) urges nations to adapt their curricula to globalisation, it also supports the maintenance of national and social cohesion by encouraging a search for specific roots and respect for national differences. In his book Art as Experience, John Dewey (Reference DEWEY1934) wrote that the communicative arena of music could go beyond functioning as merely a vehicle for entertainment, and aid in identifying connective elements within the community. Raymond Williams (Reference WILLIAMS1982: 13) has also argued that one way of viewing culture is to see it as ‘the signifying system through which . . . a social order is communicated, reproduced, experienced and explored’. Music education promotes values that are both basic to life and special to the unique socio-political features of Hong Kong in order to prepare students for national integration and global and cultural understanding (see Curriculum Development Council, 2001a, 2001b, 2002, 2003). With a view to understanding and realising the multidimensional character of music education, music learning should be considered in a much broader and wider context within and without formal institutional settings. As the post-colonial government has actively selected and promoted new sociopolitical values in Hong Kong society and schools, questions of how to encourage students to develop national and global awareness through the music curriculum and community education will continue to be contentious.
Conclusions
School music education has changed considerably in response to the development of government, politics and culture in Hong Kong society. As Hong Kong education continues to change towards its function within the PRC, it is questionable to what extent it is possible to articulate the concept of ‘one country, two systems’ in school music education, whilst at the same time building a productive, educated generation who are prepared for global and national contexts. This study was concerned with exploring young students' understanding of multicultural education and music teachers' attitudes toward the issues and challenges of multicultural education, including Chinese music teaching in their schools. It has been argued that despite the promotion of the official music curriculum, students and teachers have been slow to take up its recommendations to teach other musical cultures. Owing to the available resources and the training of music teachers, creating a truly multicultural music education curriculum may be problematic. The tensions also posed by the complex relationship between cultural diversity and political change are reflected in the crisis of national identity in mainland China. Musical culture should be studied in a context in which students are linked through their community and nation with people in other communities and nations throughout the world. How the balance between the political and global impositions on school education in the future SAR will be affected by recent developments remains to be seen. The outcome depends also on music educators' ability and willingness to develop an appropriate curriculum for students while taking in considerations of learning interests, and to motivate and widen students' musical horizons.
Acknowledgements
The authors acknowledge with gratitude the generous support of the Hong Kong Research Grant Council for the Public Policy Research project (HKBU 2004-PPR-2) without which the timely production of the current article would not have been feasible. The authors would also like to acknowledge the help and support of the participants in the research study from which this paper derives, and to express their sincere gratitude to the anonymous reviewers for their valuable and insightful comments on a previous version of the paper. Our thanks also go to the editors who provided valuable suggestions and constructive comments on the final draft of the paper.
