REVISITING CLASSROOM ENVIRONMENT AND ACADEMIC PERFORMANCE OF THE STUDENTS IN HIGHER EDUCATION INSTITUTIONS

This paper aimed to examine higher education institutions, classroom environment, the role of teacher, and student academic performance using bibliometric analysis from 2001 to 2020. The main aim was to consolidate the published researches on the students’ academic performance in higher education in the Web of Science indexed documents. There was a lack of quantitative measurements on the subject. We used the bibliometric method and a total of 2797 published documents were found. The study findings showed that the topic of ‘higher education institutions’ was on top with a total number of 2210 publications, 1822 articles as a type of published documents, 2447 publications in English, and a considerable increase in publications as per years were found. The top author named Lepori B was found with 202 citations and 13 articles started from 2007. Similarly, the University of Aveiro was on top organizations out of 2609, United States (US) on top out of 126 countries, and higher education as a keyword out of 6497. The Journal of Cleaner Production placed at top of sources out of 1551, and Portuguese Foundation for Science and Technology as a top funding agency. Furthermore, the trend of data is described in tables and figures.

of Hernández-Torrano and Kuzhabekova (2020) also asserted the development and state of research in the field of education employing bibliometric analysis over 60 years.Besides, Cretu and Morandau (2020) concluded in their study using bibliometric analysis of educational research on teacher education for inclusive education.It was also reported that several studies had been employed bibliometric analysis to examine the published documents including article, books, abstracts, letters, and other related scientific documents (Aparicio et al., 2020;El-Alfy & Mohammed, 2020;Goksu, Ozkaya, & Gunduz, 2020;Ivanović & Ho, 2019;Muhuri et al., 2019).Thus, based on the review of literature, this study aimed to examine scientific documents on higher education institutions, classroom environment, the role of teacher, and student academic performance using bibliometric analysis from 2001 to 2020.

MATERIALS AND METHODS
For the present study, researchers used the bibliometric analysis technique to conduct the present study.For bibliometric analysis, researchers extracted data from the Science Citation Index database, Web of Science (Core Collection).researchers used search query as TITLE: ("Role of teacher") OR TITLE: ("Student academic performance") OR TITLE: ("Higher education institutions") OR TITLE: ("Classroom environment") with a period of 2001 to 2020.With the help of these queries, a total of 2797 published documents were found and further analysis was employed.The indexes in the core collection of Web of Science were SCI-EXPANDED, SSCI, A&HCI, CPCI-S, CPCI-SSH, ESCI, CCR-EXPANDED, and IC.The data was extracted on February 02, 2021, at 01:00 PM (GMT).Researchers used Biblioshiny, VOSviewer, and MS Excel software for bibliometric analysis.Further, data was presented in tables and figures to show the results, and a conclusion was drawn.

RESULTS AND DISCUSSIONS
This section provides the results derived from bibliometric analysis of 2001-2020 on students' academic performance in higher education.Further, this section is divided into different sections based on the objectives of the study along with discussion.Objective 1: To examine the published documents by their topics and document types on the subject under hand during [2001][2002][2003][2004][2005][2006][2007][2008][2009][2010][2011][2012][2013][2014][2015][2016][2017][2018][2019][2020] Table 1 described the distribution of published documents by their topics and document types from 2001 to 2020.Section-a of the table was focused on the topic of the document.Data in the table revealed that 79.01 percent of the published documents were on higher education institutions and 9.76 percent of the publications were on classroom environment during 2001-2020.On the other hand, there was a smaller portion of published documents title on the role of the teacher (7.33%) and student academic performance (3.9%).It asserted that the majority (79.01%) of the published documents were on higher education institutions topic (See Table 1).Thus, higher education institutions were a very important topic for authors and used as a topic for publication.The study findings were also supported by the findings of Earp (2010) and Thanuskodi (2010).Section-b of table 1 highlighted the type of the published documents during 2001-2020.There were 65.14 percent of the published documents were in article form and 29.07 percent of documents were as proceedings papers during 2001-2020.Similarly, 1.86 percent of the documents were published as a review and only 0.14 percent of them were named as a letter.Further, a similar proportion of published documents were reported as editorial material (1.47%) and meeting abstract (1.43%).Based on the data, it concluded that more than half of the published documents were published as an article.Hence, the article as a document was very important for authors and published during 2001-2020.Furthermore, the study findings were aligned with the findings of Yanniris and Huang (2018).Objective 2: To find out the published documents by their language and years on the subject under hand during [2001][2002][2003][2004][2005][2006][2007][2008][2009][2010][2011][2012][2013][2014][2015][2016][2017][2018][2019][2020] Table 2 described the distribution of published documents by their language and year of publication from 2001 to 2020.Section-a of the table was focused on the language of the document.Data in the table revealed that 87.487 percent of the documents were published in the English language and 4.719 percent of the publications were published in the Spanish language during 2001-2020.On the other hand, there was a smaller portion of published documents in the language of Chinese (0.143%), German (0.215%), and French (0.215%).However, a similar proportion of published documents was reported in Bulgarian and Malay language as 0.107 percent.Further, documents published in the language of Czech, Latvian, Lithuanian, and Ukrainian were also reported as parallel proportion i.e., 0.072.Nonetheless, among the top twenty languages of published documents, there was a similar and smaller proportion of Afrikaans, Arabic, Catalan, Dutch, Italian, Korean, Norwegian, and Slovak reported as 0.036 percent.It asserted that the majority (87.487%) of the published documents were published in the English language during 2001-2020.Thus, the English language was very important for authors and used as a language of published documents.It is pertinent to mention here that the English language is an international language (See Table 2).Thus, the authors selected this language for wider readership for their research documents.The study findings were also supported by the findings of Ivanović and Ho (2019).
Section-b of the table was focused on the distribution of publications by their years.Data in the table revealed that 12.656 percent of the documents were published in 2020 and 13.371percent of the publications were published in 2019.On the other hand, there was a smaller portion of published documents in the year 2018 (11.334%), 2017 (10.583%), 2016 (7.758%), and 2015 (6.793%).However, a smaller proportion of published documents was also reported in the year 2003 (0.322%) and 2002 (0.501%).However, a similar proportion of published documents was reported in 2001 and 2004 (0.644%).It affirmed that a higher number of documents (728 in numbers) were published in 2019 and 2020 as compared to other years (See Table 2).The study findings were also supported by the findings of Muhuri et al. (2019) and Abedin et al. (2020).Objective 3: To chalk out published documents by their top twenty results of authors' information on the subject under hand during 2001-2020 Table 3 described the distribution of published documents by their top twenty results out of a total of 6598 authors' information from 2001 to 2020.It is pertinent to mention here that single-authored documents were 589 and multi-authored documents were found as 6009 in numbers.Data in the table revealed that the top author name was Lepori B having h_index 0f 9, g_index 0f 13, m_index of 0.6, total citations 202, with 13 publications starting from 2007.Similarly, Carvalho T had 7 publications with 110 citations, Leal W had 7 publications with 47 citations, and Soon NK had only 6 publications with 7 citations starting from 2015.Conversely, the author named Nazem F appeared in the top twenty authors with 5 publications and zero citations starting from 2008.It stated that an author named Lepori B was at top of the authors' information list with 13 publications and 202 citations (See Table 3).The study findings were also supported by the findings of Aparicio et al. (2020) and Baker et al. (2020) 4 & Figure 1).It is important to mention here that several studies reported the name of top organizations based on published documents (Cretu & Morandau, 2020;El-Alfy & Mohammed, 2020;Goksu et al., 2020).4 was focused on the list of publications by the top twenty countries from 2001 to 2020.Data in the table revealed that 0.11154 percent of the documents were published in the United States and 0.06981 percent of the publications were published in China during 2001-2020.On the other hand, there was a smaller portion of published documents in the United Kingdom (0.06201%), Brazil (0.05694%), and Malaysia (0.04446%).However, a similar proportion of published documents was reported in Colombia and Poland as 0.01872 percent.Further, documents published in Indonesia (0.01482%), Croatia (0.01677%), Romania (0.01833%), and Mexico (0.01911%) were also reported in the top twenty countries.Nonetheless, among the top twenty languages of published documents, there was a smaller proportion of Pakistan i.e., 0.01326 percent out of 2797 documents.It asserted that the name of the US was on top of twenty countries based on published documents from 2001 to 2020.As the US was English speaking country and used English as a language of published documents.It is pertinent to mention here that the English language is an international language and the US was on top of twenty countries based on publications on the subject underhand (See Table 4 & Figure 2).Thus, the authors selected their language for wider readership for their research documents.The study findings were also supported by the findings of Huang et al. (2020) and Schiuma et al. (2020).Table 5 presented the top twenty keywords used in the published documents during 2001-2020.Data in the table pointed out that higher education was on the top of the top twenty keywords with a total number of 492 and higher education institutions placed at second number with a total number of 351 as occurrence.Similarly, universities used as keyword 67 times and university as 55 times in the published documents from 2001 to 2020.Further, sustainability, education, sustainable development, quality assurance, quality, management, knowledge management, students, innovation, evaluation, elearning, efficiency, and governance was also used as the top twenty keywords in a published document in the said period of publication.However, governance and strategy were used as lowest as a keyword in the top twenty keywords in published documents in 20 years.It is important to mention here that the total keywords were 6497 in the number used in the published documents.The keywords as higher education and higher education institutions were on the top of the list of top twenty keywords (See Table 5 & Figure 3).The study findings are aligned with the findings calculated keywords in the published documents such as Kuzhabekova (2021), El-Alfy and Mohammed (2020), and Aparicio et al. (2020).6).The study findings are aligned with the findings of several researchers' analyzed top sources of published documents.8).

CONCLUSION
Based on the bibliometric analysis, researchers reached the conclusion that this method enabled researchers to gain more in-depth insights into the selected topic and support to recognize variables that were used during research in the students' academic performance in higher education institutions.The study was mainly based to examine higher education institutions, classroom environment, the role of teacher, and students' academic performance-oriented published documents indexed in Web of Science from 2001 to 2020.It concluded that the topic of 'higher education institutions' was on top with a total number of 2210 publications in form of articles in the English language from the US.Further, the top author's name was Lepori B and the University of Aveiro was of the top organizations.The keyword 'higher education' was highly used and the top publications were in the 'Journal of Cleaner Production' and the Portuguese Foundation for Science and Technology as a top funding agency.It is recommended that further bibliometric studies may be conducted from other databases and using other students' academic performance in higher education-related topics.

Limitations of the Study
The present bibliometric study was based on publications in the Web of Science only and researchers did not use other databases agencies.Further, it only focussed to examine higher education institutions, classroom environment, the role of teacher, and student academic performance using bibliometric analysis from 2001 to 2020.Thus, researchers did not use other related topics including study culture, students' family, parental involvement, and gender, etc.

Figure 1 .
Figure 1.Published Documents by Top Twenty Organizations (2001-2020) Objective 4: To determine the published documents by top twenty organizations and counties on the subject under hand during 2001-2020 Table 4 revealed the top twenty names out of 2609 organizations and countries (126 in total numbers) based on published documents during 2001-2020.Section-a of the table was based on the top twenty organizations.Data indicated that the University of Aveiro was at the top of the list with 26 number of published documents (0.93% out of 2797.In second place, the University of Lisbon was standing with 21 publications from 2001 to 2020.Further, the University of Beira Interior and the University of Pretoria had the same number of publications i.e., 19 in number.On the other hand, the name of Hamburg Univ.Appl.Sci. was at bottom of the top twenty organizational published documents from 2001 to 2020 (See Table4& Figure1).It is important to mention here that several studies reported the name of top organizations based on published documents(Cretu & Morandau, 2020;El-Alfy & Mohammed, 2020;Goksu et al., 2020).

Figure3.
Figure3.Published Documents by Top TwentyKeywords (2001Keywords ( -2020)  )   As well as the concern of sources of publications, Journal of Cleaner Production placed at top of sources out of 1551 with h_index of 14, g_index of 24, m_index of 1.272727273, total citations of 609, total publications 27, and publication year starting from 2011.Further, Higher Education was placed at second number with h_index of 13, g_index of 22, total citations of 512, total publications 34, and publication year starting from 2002.However, Quality Assurance in Education was placed at bottom of sources of top twenty published documents during 2001 to 2020 with h_index of 4, g_index of 6, m_index of 0.444444444, total citations of 48, total publications 10, and publication year starting from 2013.It is pertinent to mention here that the Journal of Cleaner Production was placed at the top and Quality Assurance in Education placed at bottom of the top twenty sources of published documents (see Figure4, Appendix A, Table 6).The study findings are aligned with the findings of several researchers' analyzed top sources of published documents.

Figure 4 .
Figure 4. Published Documents by Top Twenty Sources of Publications (2001-2020) Further, the Portuguese Foundation for Science and Technology was in the top list of Published Documents by Top Twenty Funding Agencies during 2001-2020.Similarly, CAPES, European Union EU, and National Natural Science Foundation of China NSFC was placed at second position with 0.465 percent of 2797 in published documents.On the other hand, the Australian Research Council and European Social Fund ESF with the same proportion (0.179% out of 2797) were placed at bottom of the top twenty funding agencies/organizations of published documents from 2001 to 2020 (see Appendix B, Table 7).As well as the concern of the top twenty articles with citations, an article titled, 'perceptions of the classroom environment, achievement goals, and achievement outcomes' [written by Church, MA; Elliot, AJ; Gable, SL in 2001, ISSN-0022-0663, Vol./No.93(1)] with total citations of 433 was listed at top of the list during 2001-2020.Conversely, an article titled, 'implementing an international approach to English pronunciation: the role of teacher attitudes and identity' [written by Jenkins, J in 2005, ISSN-0039-8322, Vol./No.39(3)] with total citations of 90 was placed at bottom of the top twenty published documents during the said time period (see Appendix C, Table8).

Table 2
Distribution of Published Documents by TheirLanguage and Years (2001-2020)

Table 3
Distribution of Published Documents by Their Top Twenty Results ofAuthors' Information (2001-2020)

Table 4
Distribution of Published Documents by Top TwentyOrganizations and Counties (2001-2020)

Table 5
Distribution of Published Documents by Top TwentyKeywords (2001Keywords ( -2020)  ) Culture Sports Science and Technology Japan MEXT 0.250 National Council for Scientific and Technological Development CNPQ 0.250 NIH Eunice Kennedy Shriver National Institute of Child Health Human