Quantitative and Qualitative Analysis of Distance Learning in Dental Education During COVID-19 Outbreak
Year 2025,
Volume: 9 Issue: 1, 9 - 17, 30.04.2025
Hatice Kalender
,
Şükrü Can Akmansoy
,
Zehra Özge Çandereli
,
Tuğba Emine Beyhan
,
Burcu Aksoy
,
Mehmet Özyurt
,
Nur Şişman Kitapçı
,
Berceste Polat Akmansoy
,
Okan Cem Kitapçı
,
Nuri Sertaç Sırma
Ümit Karaçaylı
,
Meral Yay
,
John Ag Buchanan
Farida Fortune
,
Yasemin Özkan
,
Gonca Mumcu
Abstract
Aim: The aim of this study was to analyse the feedbacks that dental students provided about Distance Learning (DL) and to find clues regarding readiness for possible national or global emergencies during a potential COVID-19 outbreak by using both Quantitative and Qualitative Methods.
Method: This cross-sectional study involved 608 dental students (F/M: 405/203). Data were collected by using online Focus-Group discussions as a Qualitative method and electronic-questionnaires (E-Questionnaire) as a Quantitative method. In both methods, students were asked to evaluate questions or statements focused on cognitive load and the advantages and disadvantages of DL. Moreover, in the E-Questionnaire, the integration of technology into the dental education was evaluated by Tendency Scale for Technology Use in Class (TSTUC). Factor analysis was carried out for construct validity of the TSTUC scale. Items regarding “Internalizing the professional environment” and “Critical thinking” were used for content validity of the TSTUC scale.
Results: Two subtopics, namely “Technology Use” and “Motivation and Technology” were defined for TSTUC scale in the Factor Analysis. Elevated scores were observed in dental students’ responses, whose professional improvements regarding “Internalizing the professional environment” (4,214±0,630 vs 3,991±0,766)” and “Critical thinking” (4,026±0,683 vs 3,667±0,891)” were positively affected by DL (p<0.05). The lowest scores for items regarding “DL increased Motivation”, “DL increased Student-Course Content Interaction", and “DL increased Student-Lecturer Interaction” were observed in the first-year students’ responses (p<0,05).
During the focus-Group discussions, “Difficulties in the Understanding of the Course Content”, “Inability to Relate Theoretical Knowledge with Practice”, “Insufficient Interactions between the Students and Lecturers” were defined to be the main problems regarding DL.
Conclusion: Future DL strategies for national or international emergencies should be taken into account, considering the constraints of DL for dentistry students' professional developments as well as effective ways of corporating technology into education. Moreover, TSTUC scale was found to be a valid and reliable tool to evaluate the implementation of DL for dental students’ education.
References
- Abbasi MS, Ahmed N, Sajjad B, Alshahrani A, Saeed S, Sarfaraz S, Alhamdan RS, Vohra F, Abduljabbar T. E-Learning perception and satisfaction among health sciences students amid the COVID-19 pandemic. Work. 2020;67(3):549-56.
- Ali W. Online and remote learning in higher education institutes: A necessity in light of COVID-19 pandemic. HES. 2020;10(3):16-25.
Alkadi L. Dental education in the COVID-19 era: Challenges, solutions and opportunities. The Open Dent J. 2021;15(1).
- Almeida F, Monteiro J. Challenges of assessing and evaluating the students at distance. JOHE. 2021;5(1):3-10.
Amir LR, Tanti I, Maharani DA, Wimardhani YS, Julia V, Sulijaya B, Puspitawati R. Student perspective of classroom and distance learning during COVID-19 pandemic in the undergraduate dental study program Universitas Indonesia. BMC Med Educ. 2020;20(1)-392-399.
- Ayyıldız S, Çandereli ZÖ, Kılıç-Aksu P, Çatar RÖ, Kitapçı OC, Şişman-Kitapçı N, Köksal L, Demirgöz-Bal M, Mumcu G. Assessment of students' anxiety level and technology readiness in a simulation-based obstetrics training. HUHEMFAD. 2022;9(3):264-73.
- Barabari P, Moharamzadeh K. Novel coronavirus (COVID-19) and dentistry–A comprehensive review of literature. Dentistry Journal. 2020;8(2):53.
- Bilgiç HG, Tuzun H. Issues and challenges with web-based distance education programs in Turkish higher education institutes. TOJDE. 2020;21(1):143-64.
- Chang TY, Hong G, Paganelli C, Phantumvanit P, Chang WJ, Shieh YS, Hsu ML. Innovation of dental education during COVID-19 pandemic. JDS. 2021;16(1):15-20.
- Chung E, Subramaniam G, Dass LC. Online learning readiness among university students in Malaysia amidst COVID-19. AJUE. 2020;16(2):46-58.
- Cidral WA, Oliveira T, Di Felice M, Aparicio M. E-learning success determinants: Brazilian empirical study. Computers & Education. 2018;122:273-90.
- Clemente MP, Moreira A, Pinto JC, Amarante JM, Mendes J. The challenge of dental education after COVID-19 pandemic - present and future innovation study design. Inquiry. 2021;58:1-8.
- Cobanoglu AA, Cobanoglu I. Do Turkish student teachers feel ready for online learning in post-covid times? A study of online learning readiness. TOJD. 2021;22(3):270-80.
- Costa ED, Brasil DM, Santaella GM, Cascante-Sequeira D, Ludovichetti FS, Freitas DQ. Impact of COVID-19 pandemic on dental education: perception of professors and students. Odovtos-Int. J. Dent. Sc. 2022;24(1):122-33.
- De Wever B, Schellens T, Valcke M, Van Keer H. Content analysis schemes to analyze transcripts of online asynchronous discussion groups: A review. Computers & Education. 2006;46(1):6-28.
- Deshpande S, Chahande J, Rathi A. Mobile learning app: A novel method to teach clinical decision making in prosthodontics. Educ. Health. 2017;30(1):31-4.
- Dost S, Hossain A, Shehab M, Abdelwahed A, Al-Nusair L. Perceptions of medical students towards online teaching during the COVID-19 pandemic: a national cross-sectional survey of 2721 UK medical students. BMJ Open. 2020;10(11):1-10
- Elangovan S, Mahrous A, Marchini L. Disruptions during a pandemic: Gaps identified and lessons learned. J Dent Educ. 2020;84(11):1270-4.
- Estriegana R, Medina-Merodio J-A, Barchino R. Student acceptance of virtual laboratory and practical work: An extension of the technology acceptance model. Computers & Education. 2019;135:1-14.
- Günüç S, Kuzu A. Tendency scale for technology use in class: Development, reliability and validity. EKU. 2014;10(4):863-84.
- Haroon Z, Azad AA, Sharif M, Aslam A, Arshad K, Rafiq S. COVID-19 era: Challenges and solutions in dental education. J Coll Physicians Surg Pak. 2020;30(10):129-31.
- Herr L, Jih MK, Shin J, Chae YK, Lee HS, Choi SC, Nam OH. The perspective of undergraduate dental students on web-based learning in pediatric dentistry during the COVID-19 pandemic: a Korean multicenter cross-sectional survey. BMC Med Educ. 2021;21(1):505-513.
- Horzum MB, Kaymak ZD, Gungoren OC. Structural equation modeling towards online learning readiness, academic motivations, and perceived learning. JESTP. 2015;15(3):759-770.
- Ilić J, Radović K, Savić-Stanković T, Popovac A. The effect of COVID-19 pandemic on final year dental students’ self-confidence level in performing clinical procedures. PlosOne. 2021; 6: e0257359.
- Iturbe-LaGrave V. Teaching Through a Pandemic: Cognitive Load, Mental Health and Learning Under Stress. Denver: Office of Teaching&Learning; 2020. [cited 07.01.2023]. Available from: https://otl.du.edu/teaching-through-a-pandemic-cognitive-load-mental-health-and-learning-under-stress/
- Ivanka, D. V., & Teodor, Y. V. Effect of e-learning and Covid 19 on the quality of practical endodontic treatment by final year students. IJODM. 2023;1(1):1-4.
- Kaya Z, Tan S. New trends of measurement and assessment in distance education. TOJDE. 2014;15(1):206-17.
- Loch C, Kuan IB, Elsalem L, Schwass D, Brunton PA, Jum'ah A. COVID‐19 and dental clinical practice: Students and clinical staff perceptions of health risks and educational impact. JDE. 2021;85(1):44-52.
- Machado RA, Bonan PRF, Perez Dedc, Martelli H. COVID-19 pandemic and the impact on dental education: Discussing current and future perspectives. Braz. Oral Res. 2020;34:1-6.
- Mahlangu VP. The Good, the Bad, and the Ugly of Distance Learning in Higher Education. Sinecen M, editors. Trends in E-learning. United Kingdom: InTech; 2018. p.17-29.
- Moazami F, Bahrampour E, Azar MR, Jahedi F, Moattari M. Comparing two methods of education (virtual versus traditional) on learning of Iranian dental students: A post-test only design study. BMC Med. Educ. 2014;14(1):45-49.
- Mosa AA, Mahrin MNrb, Ibrrahim R. Technological aspects of e-learning readiness in higher education: A review of the literature. Comput Inf Sci. 2016;9(1):113-27.
- Nortvig A-M, Petersen AK, Balle SH. A literature review of the factors influencing e‑learning and blended learning in relation to learning outcome, student satisfaction and engagement. EJEL. 2018;16(1):46‑55.
- Pontual MLA, do Nascimento EHL, da Cruz Perez DE, Pontual AA, Ramos-Perez FM. Challenges in oral radiology teaching during COVID-19 pandemic. DMFR. 2020;49(5):20200178.
- Qualtrough A. Undergraduate endodontic education: what are the challenges? BDJ. 2014;216(6):361-4.
- Rohayani AHH, Kurniabudi, Sharipuddin. A literature review: Readiness factors to measuring e-learning readiness in higher education. Procedia Computer Science. 2015;59:230-4.
- Samra RK, Nirola A, Verma A, Nagpal A, Thakur M. Dental students' perception on the impact of e-learning in continuing dental education during the current pandemic scenario. IJDS. 2021;13(2):61.
- Schlenz MA, Schmidt A, Wöstmann B, Krämer N, Schulz-Weidner N. Students’ and lecturers’ perspective on the implementation of online learning in dental education due to SARS-CoV-2 (COVID-19): a cross-sectional study. BMC Med. Educ. 2020;20(1)354-360.
- Sharka R, Abed H, Dziedzic A. Can undergraduate dental education be online and virtual during the COVID-19 era? Clinical training as a crucial element of practical competencies. MedEdPublish. 2020;9:215-222.
- Silva PGB, de Oliveira CAL, Borges MMF, Moreira DM, Alencar PNB, Avelar RL, Bitu Sousa RMR, Sousa FB. Distance learning during social seclusion by COVID‐19: Improving the quality of life of undergraduate dentistry students. Eur J Dent Educ. 2021;25(1):124-34.
- Tzafilkou K, Perifanou M, Economides AA. Negative emotions, cognitive load, acceptance, and self-perceived learning outcome in emergency remote education during COVID-19. Education and Information Technologies. 2021;26(6):7497-521.
- UNESCO. [cited 07.01.2023]. Available from: https://www.weforum.org/agenda/2020/04/coronavirus-education-global-covid19-online-digital-learning/. 2020.
- Varoni EM, Sardella A, Lodi G, Iriti M, Carrassi A. COVID-19 and dental education: The experience of the dental school from the University of Milan. Med. Sci. Edu. 2022;32(2):539-44.
Wang K, Zhang L, Ye L. A nationwide survey of online teaching strategies in dental education in China. JDE. 2021;85(2):128-34.
Wei H-C, Chou C. Online learning performance and satisfaction: do perceptions and readiness matter? Distance Education. 2020;41(1):48-69.
Yilmaz R. Exploring the role of e-learning readiness on student satisfaction and motivation in flipped classroom. Comput. Hum. Behav. 2017;70:251-60.
Yılmaz, E. O., & Toker, T. Analysing the effects of assessment and evaluation applications and exam formats in distance education. IJPES. 2022;9(1):165-176.
COVID-19 Salgınında Diş Hekimliğinde Uzaktan Eğitimin Kantitatif ve Kalitatif Analizi
Year 2025,
Volume: 9 Issue: 1, 9 - 17, 30.04.2025
Hatice Kalender
,
Şükrü Can Akmansoy
,
Zehra Özge Çandereli
,
Tuğba Emine Beyhan
,
Burcu Aksoy
,
Mehmet Özyurt
,
Nur Şişman Kitapçı
,
Berceste Polat Akmansoy
,
Okan Cem Kitapçı
,
Nuri Sertaç Sırma
Ümit Karaçaylı
,
Meral Yay
,
John Ag Buchanan
Farida Fortune
,
Yasemin Özkan
,
Gonca Mumcu
Abstract
Amaç: Bu çalışmanın amacı, COVID-19 pandemisi sebebiyle uygulanan uzaktan eğitimin lisans diş hekimliği eğitimine etkilerini kantitatif ve kalitatif yöntemlerle değerlendirmektir.
Yöntem: Bu kesitsel çalışmaya 608 diş hekimliği öğrencisi (K/E: 405/203) dâhil edilmiştir.
Veriler, kalitatif yöntem kullanımı ile odak grup görüşmeleri ve kantitatif yöntem kullanımı ile e-anket aracılığıyla elde edilmiştir. Her iki yöntemde de öğrencilere uzaktan eğitimin avantajları, dezavantajları ve uzaktan eğitimde bilişsel yük ile ilgili sorular sorulmuştur. Ayrıca, e-anket formunda diş hekimliği eğitimine teknolojinin entegre edilmesini değerlendirmek için “Derste Teknoloji Kullanımına Yönelik Eğilim Ölçeği (DTKEÖ)” kullanılmıştır.
Ölçeğin Yapı Geçerliliği için Açıklayıcı Faktör Analizi yapılmıştır. Ölçeğin Kapsam Geçerliliği için, UE’nin çıktıları olan “Profesyonel ortamı içselleştirme” ve “Eleştirel düşünme” maddeleri kullanılmıştır.
Bulgular: Faktör analizinde “Teknoloji Kullanımı” ile “Motivasyon ve Teknoloji” boyutları tanımlanmıştır. UE’de “Mesleki ortamı içselleştirme (4,214±0,630 vs 3,991±0,766)” ve “Eleştirel düşünme (4,026±0,683 vs 3,667±0,891)” açısından mesleki gelişimlerinin olumlu yönde etkilendiğini düşünen diş hekimliği öğrencilerinde ölçeğin her iki alt boyutuna ait puanların daha yüksek olduğu gözlenmiştir (p<0.05).
“Uzaktan eğitim motivasyonu artırır”, “Uzaktan eğitim öğrenci-ders içeriği etkileşimini artırır” ve “Uzaktan eğitim öğrenci öğretim üyesi etkileşimini arttırır” maddelerine ilişkin en düşük puanların, birinci sınıf diş hekimliği öğrencilerinin yanıtlarında gözlenmiştir (p<0,05).
Odak grup görüşmelerinde belirtilen başlıca sorunlar; ders içeriğini anlamada güçlükler, teorik bilginin klinik uygulama ile ilişkilendirilememesi, öğrenci ve öğretim üyesi etkileşiminin yetersizliğidir.
Sonuç ve Öneriler: Gelecekteki olası global düzeydeki acil durumlar için uzaktan eğitimin avantajları ve sınırlılıklarının yanı sıra diş hekimliği öğrencilerinin ihtiyaçları da göz önünde bulundurulmalıdır. Bununla birlikte DTKEÖ, diş hekimliğinde uzaktan eğitimin değerlendirilmesinde kullanılabilecek geçerli ve güvenilir bir ölçektir.
References
- Abbasi MS, Ahmed N, Sajjad B, Alshahrani A, Saeed S, Sarfaraz S, Alhamdan RS, Vohra F, Abduljabbar T. E-Learning perception and satisfaction among health sciences students amid the COVID-19 pandemic. Work. 2020;67(3):549-56.
- Ali W. Online and remote learning in higher education institutes: A necessity in light of COVID-19 pandemic. HES. 2020;10(3):16-25.
Alkadi L. Dental education in the COVID-19 era: Challenges, solutions and opportunities. The Open Dent J. 2021;15(1).
- Almeida F, Monteiro J. Challenges of assessing and evaluating the students at distance. JOHE. 2021;5(1):3-10.
Amir LR, Tanti I, Maharani DA, Wimardhani YS, Julia V, Sulijaya B, Puspitawati R. Student perspective of classroom and distance learning during COVID-19 pandemic in the undergraduate dental study program Universitas Indonesia. BMC Med Educ. 2020;20(1)-392-399.
- Ayyıldız S, Çandereli ZÖ, Kılıç-Aksu P, Çatar RÖ, Kitapçı OC, Şişman-Kitapçı N, Köksal L, Demirgöz-Bal M, Mumcu G. Assessment of students' anxiety level and technology readiness in a simulation-based obstetrics training. HUHEMFAD. 2022;9(3):264-73.
- Barabari P, Moharamzadeh K. Novel coronavirus (COVID-19) and dentistry–A comprehensive review of literature. Dentistry Journal. 2020;8(2):53.
- Bilgiç HG, Tuzun H. Issues and challenges with web-based distance education programs in Turkish higher education institutes. TOJDE. 2020;21(1):143-64.
- Chang TY, Hong G, Paganelli C, Phantumvanit P, Chang WJ, Shieh YS, Hsu ML. Innovation of dental education during COVID-19 pandemic. JDS. 2021;16(1):15-20.
- Chung E, Subramaniam G, Dass LC. Online learning readiness among university students in Malaysia amidst COVID-19. AJUE. 2020;16(2):46-58.
- Cidral WA, Oliveira T, Di Felice M, Aparicio M. E-learning success determinants: Brazilian empirical study. Computers & Education. 2018;122:273-90.
- Clemente MP, Moreira A, Pinto JC, Amarante JM, Mendes J. The challenge of dental education after COVID-19 pandemic - present and future innovation study design. Inquiry. 2021;58:1-8.
- Cobanoglu AA, Cobanoglu I. Do Turkish student teachers feel ready for online learning in post-covid times? A study of online learning readiness. TOJD. 2021;22(3):270-80.
- Costa ED, Brasil DM, Santaella GM, Cascante-Sequeira D, Ludovichetti FS, Freitas DQ. Impact of COVID-19 pandemic on dental education: perception of professors and students. Odovtos-Int. J. Dent. Sc. 2022;24(1):122-33.
- De Wever B, Schellens T, Valcke M, Van Keer H. Content analysis schemes to analyze transcripts of online asynchronous discussion groups: A review. Computers & Education. 2006;46(1):6-28.
- Deshpande S, Chahande J, Rathi A. Mobile learning app: A novel method to teach clinical decision making in prosthodontics. Educ. Health. 2017;30(1):31-4.
- Dost S, Hossain A, Shehab M, Abdelwahed A, Al-Nusair L. Perceptions of medical students towards online teaching during the COVID-19 pandemic: a national cross-sectional survey of 2721 UK medical students. BMJ Open. 2020;10(11):1-10
- Elangovan S, Mahrous A, Marchini L. Disruptions during a pandemic: Gaps identified and lessons learned. J Dent Educ. 2020;84(11):1270-4.
- Estriegana R, Medina-Merodio J-A, Barchino R. Student acceptance of virtual laboratory and practical work: An extension of the technology acceptance model. Computers & Education. 2019;135:1-14.
- Günüç S, Kuzu A. Tendency scale for technology use in class: Development, reliability and validity. EKU. 2014;10(4):863-84.
- Haroon Z, Azad AA, Sharif M, Aslam A, Arshad K, Rafiq S. COVID-19 era: Challenges and solutions in dental education. J Coll Physicians Surg Pak. 2020;30(10):129-31.
- Herr L, Jih MK, Shin J, Chae YK, Lee HS, Choi SC, Nam OH. The perspective of undergraduate dental students on web-based learning in pediatric dentistry during the COVID-19 pandemic: a Korean multicenter cross-sectional survey. BMC Med Educ. 2021;21(1):505-513.
- Horzum MB, Kaymak ZD, Gungoren OC. Structural equation modeling towards online learning readiness, academic motivations, and perceived learning. JESTP. 2015;15(3):759-770.
- Ilić J, Radović K, Savić-Stanković T, Popovac A. The effect of COVID-19 pandemic on final year dental students’ self-confidence level in performing clinical procedures. PlosOne. 2021; 6: e0257359.
- Iturbe-LaGrave V. Teaching Through a Pandemic: Cognitive Load, Mental Health and Learning Under Stress. Denver: Office of Teaching&Learning; 2020. [cited 07.01.2023]. Available from: https://otl.du.edu/teaching-through-a-pandemic-cognitive-load-mental-health-and-learning-under-stress/
- Ivanka, D. V., & Teodor, Y. V. Effect of e-learning and Covid 19 on the quality of practical endodontic treatment by final year students. IJODM. 2023;1(1):1-4.
- Kaya Z, Tan S. New trends of measurement and assessment in distance education. TOJDE. 2014;15(1):206-17.
- Loch C, Kuan IB, Elsalem L, Schwass D, Brunton PA, Jum'ah A. COVID‐19 and dental clinical practice: Students and clinical staff perceptions of health risks and educational impact. JDE. 2021;85(1):44-52.
- Machado RA, Bonan PRF, Perez Dedc, Martelli H. COVID-19 pandemic and the impact on dental education: Discussing current and future perspectives. Braz. Oral Res. 2020;34:1-6.
- Mahlangu VP. The Good, the Bad, and the Ugly of Distance Learning in Higher Education. Sinecen M, editors. Trends in E-learning. United Kingdom: InTech; 2018. p.17-29.
- Moazami F, Bahrampour E, Azar MR, Jahedi F, Moattari M. Comparing two methods of education (virtual versus traditional) on learning of Iranian dental students: A post-test only design study. BMC Med. Educ. 2014;14(1):45-49.
- Mosa AA, Mahrin MNrb, Ibrrahim R. Technological aspects of e-learning readiness in higher education: A review of the literature. Comput Inf Sci. 2016;9(1):113-27.
- Nortvig A-M, Petersen AK, Balle SH. A literature review of the factors influencing e‑learning and blended learning in relation to learning outcome, student satisfaction and engagement. EJEL. 2018;16(1):46‑55.
- Pontual MLA, do Nascimento EHL, da Cruz Perez DE, Pontual AA, Ramos-Perez FM. Challenges in oral radiology teaching during COVID-19 pandemic. DMFR. 2020;49(5):20200178.
- Qualtrough A. Undergraduate endodontic education: what are the challenges? BDJ. 2014;216(6):361-4.
- Rohayani AHH, Kurniabudi, Sharipuddin. A literature review: Readiness factors to measuring e-learning readiness in higher education. Procedia Computer Science. 2015;59:230-4.
- Samra RK, Nirola A, Verma A, Nagpal A, Thakur M. Dental students' perception on the impact of e-learning in continuing dental education during the current pandemic scenario. IJDS. 2021;13(2):61.
- Schlenz MA, Schmidt A, Wöstmann B, Krämer N, Schulz-Weidner N. Students’ and lecturers’ perspective on the implementation of online learning in dental education due to SARS-CoV-2 (COVID-19): a cross-sectional study. BMC Med. Educ. 2020;20(1)354-360.
- Sharka R, Abed H, Dziedzic A. Can undergraduate dental education be online and virtual during the COVID-19 era? Clinical training as a crucial element of practical competencies. MedEdPublish. 2020;9:215-222.
- Silva PGB, de Oliveira CAL, Borges MMF, Moreira DM, Alencar PNB, Avelar RL, Bitu Sousa RMR, Sousa FB. Distance learning during social seclusion by COVID‐19: Improving the quality of life of undergraduate dentistry students. Eur J Dent Educ. 2021;25(1):124-34.
- Tzafilkou K, Perifanou M, Economides AA. Negative emotions, cognitive load, acceptance, and self-perceived learning outcome in emergency remote education during COVID-19. Education and Information Technologies. 2021;26(6):7497-521.
- UNESCO. [cited 07.01.2023]. Available from: https://www.weforum.org/agenda/2020/04/coronavirus-education-global-covid19-online-digital-learning/. 2020.
- Varoni EM, Sardella A, Lodi G, Iriti M, Carrassi A. COVID-19 and dental education: The experience of the dental school from the University of Milan. Med. Sci. Edu. 2022;32(2):539-44.
Wang K, Zhang L, Ye L. A nationwide survey of online teaching strategies in dental education in China. JDE. 2021;85(2):128-34.
Wei H-C, Chou C. Online learning performance and satisfaction: do perceptions and readiness matter? Distance Education. 2020;41(1):48-69.
Yilmaz R. Exploring the role of e-learning readiness on student satisfaction and motivation in flipped classroom. Comput. Hum. Behav. 2017;70:251-60.
Yılmaz, E. O., & Toker, T. Analysing the effects of assessment and evaluation applications and exam formats in distance education. IJPES. 2022;9(1):165-176.