Управленец2218-50032686-792310.29141/2218-5003-2025-16-1-7https://elibrary.ru/item.asp?id=80429158https://elibrary.ru/item.asp?id=80429158Потребительский выбор товаров в интернете и прогнозирование ассортимента методом АВС-анализа на основе метрик визуального нейромаркетингаConsumers’ online shopping choices and assortment forecasting by ABC analysis using eye tracking technologyКальковаН. Н.КальковаН. Н.KalkovaN. N.nkalkova@yandex.ruV.I. Vernadsky Crimean Federal UniversityКрымский федеральный университет имени В.И. Вернадского12032025161921051204202419062024CC BY-NC 4.0Н.Н. КальковаN.N. Kalkova

Развитие интернет-торговли ограничивает возможность изучения потребительского поведения традиционными маркетинговыми методами. Статья направлена на выявление особенностей прогнозирования потребительского выбора товаров (на примере сыра) в интернете с использованием технологии окулографии (eye-tracking). Методологической основой послужила теория сенсорного маркетинга. Информационную базу исследования составили окулографические данные 30 испытуемых, полученные в ходе лабораторного нейромаркетингового эксперимента по изучению товаров в трех интернет-магазинах: с низкой, средней и высокой плотностью размещенных товаров. Использовались общенаучные и экономико-статистические методы анализа, а также нейрофизиологические методы для оценки реакции потребителей в процессе визуального изучения товаров на виртуальных полках интернет-магазинов. На основе анализа паттернов глазодвигательного поведения определены гендерные различия при просмотре интернет-страниц. Установлено, что визуальная реакция на товар в виде максимального количества фиксаций на нем выступает определяющей метрикой, что дает возможность с высокой точностью прогнозировать выбор товара потребителями на виртуальной странице. Предложено ранжировать товары по степени их вероятного выбора на базе АВС-анализа, который апробирован на примере онлайн-страниц с низкой и средней плотностью размещения продукции. Результаты показали, что количество фиксаций на товарах на виртуальной полке связано с когнитивным потребительским поведением при их выборе. Предложенная методика позволяет с высокой долей вероятности прогнозировать потребительский выбор товаров на интернет-странице и, как следствие, более рационально планировать ассортимент и товарные запасы, а также эффективно продвигать продукт в виртуальной среде.

Amid the thriving e-commerce, traditional marketing methods are getting obsolete in examining consumer behaviour. Using the case study of cheese, the paper aims to reveal peculiarities of forecasting consumers’ online shopping choices with the help of eye-tracking technology. The concept of sensory marketing constitutes the methodological basis of the study. The evidence base was formed by the results of a neuromarketing experiment (30 experimental subjects) on investigating three online stores with different shelf space allocation (low, middle or high density of products). The research employs general scientific and economic-statistical methods, as well as neurophysiological methods to assess consumers’ reaction during the visual examination of goods on the stores’ virtual shelves. Having analysed eye movement patterns, we determined gender differences in viewing web pages. The visual reaction to a product expressed in the maximum number of fixations was found to be a determining metric that allows predicting consumer choice when shopping online. The products were ranked according to the likelihood of them being chosen by consumers based on ABC analysis that was tested using online pages with low and medium product density. The results showed that the number of fixations on products on the virtual shelf is associated with cognitive consumer behaviour when making a choice. The proposed method allows predicting consumers’ online shopping choices, which can help manufacturers more rationally plan their assortment and inventory and effectively promote products in a virtual environment.

интернетнейромаркетингпотребительское поведениевизуальное восприятиесырайтрекингАВС-анализcheesevisual perceptionconsumer behaviourneuromarketingthe Interneteye trackingАВС analysisAkulich M.V. (2016). Internet marketing. Moscow: Dashkov i Ko Publ. (in Russ.)Акулич М.В. (2016). Интернет-маркетинг. Москва: Дашков и Ко.Ivashkin M.V., Kolesnikov A.V., Otteva I.V. (2022). Internet merchandising: Concept and specifics of use in modern retail. Gumanitarnye, sotsialno-ekonomicheskie i obshchestvennye nauki / Humanities, Social-Economic and Social Sciences, no. 12-1, pp. 130–135. https://doi.org/10.17150/2500-2759.2020. (in Russ.)Ивашкин М.В., Колесников А.В., Оттева И.В. (2022). Интернет-мерчандайзинг: понятие и специфика использования // Гуманитарные, социально-экономические и общественные науки. № 12 (1). С. 130-135. https://doi.org/10.17150/2500-2759.2020.Kalkova N.N., Yarosh O.B., Kalkov D.A. (2024). Computer program “Estimation of probability of consumer choice of goods in online environment by ABC-analysis method based on visual neuromarketing data”. Copyright certificate of the state registration of the computer program no. RU2024617947. Simferopol: V.I. Vernadsky Crimean Federal University. (in Russ.)Калькова Н.Н., Ярош О.Б., Кальков Д.А. (2024). Программа для ЭВМ "Оценка вероятности потребительского выбора товаров в онлайн-среде методом ABC-анализа на основе данных визуального нейромаркетинга": авторское свидетельство о государственной регистрации программы для ЭВМ RU2024617947 от 08.04.2024.Kalkova N.N., Yarosh O.B. (2024a). Database for estimating the probability of consumer choice of cheese in online environment by ABC analysis based on visual neuromarketing metrics with low density of placed goods. Copyright certificate of the state registration of the database no. RU2024621472. Simferopol: V.I. Vernadsky Crimean Federal University. (in Russ.)Калькова Н.Н., Ярош О.Б. (2024a). База данных оценки вероятности потребительского выбора сыра в онлайн-среде методом АВС-анализа на основе метрик визуального нейромаркетинга при низкой плотности размещенных товаров: авторское свидетельство о государственной регистрации базы данных RU2024621472 от 04.04.2024.Kalkova N.N., Yarosh O.B. (2024b). Database for estimating the probability of consumer choice of cheese in online environment by ABC analysis based on visual neuromarketing metrics with medium density of placed goods. Copyright certificate of the state registration of the database no. RU2024621473. Simferopol: V.I. Vernadsky Crimean Federal University. (in Russ.)Калькова Н.Н., Ярош О.Б. (2024b). База данных оценки вероятности потребительского выбора сыра в онлайн-среде методом АВС-анализа на основе метрик визуального нейромаркетинга при средней плотности размещенных товаров: авторское свидетельство о государственной регистрации базы данных RU2024621473 от 04.04.2024.Kalkova N.N., Yarosh O.B. (2024c). Database for estimating the probability of consumer choice of cheese in online environment by ABC analysis based on visual neuromarketing metrics with high density of placed goods. Copyright certificate of the state registration of the database no. RU2024621574. Simferopol: V.I. Vernadsky Crimean Federal University. (in Russ.)Калькова Н.Н., Ярош О.Б. (2024c). База данных оценки вероятности потребительского выбора сыра в онлайн-среде методом АВС-анализа на основе метрик визуального нейромаркетинга при высокой плотности размещенных товаров: авторское свидетельство о государственной регистрации базы данных RU2024621574 от 10.04.2024.Kazanskaya I.V., Yamshchikov S.V., Romashkina A.P. (2022). Consumption and consumer behavior in the digital age. Gumanitarnye, sotsialno-ekonomicheskie i obshchestvennye nauki / Humanities, Social-Economic and Social Sciences, no. 1, pp. 43–47. https://doi.org/10.23672/t1024-0645-1658-b. (in Russ.)Казанская И.В., Ямщиков С.В., Ромашкина А.П. (2022). Потребление и потребительское поведение в цифровую эпоху // Гуманитарные, социально-экономические и общественные науки. № 1. С. 43-47. https://doi.org/10.23672/t1024-0645-1658-b.Kerzina E.A. (2019). Neuromarketing: Methodological foundations and practical directions of application in business. Marketing v Rossii i za rubezhom / Marketing in Russia and Abroad, no. 3, pp. 13–18. (in Russ.)Керзина Е.А. (2019). Нейромаркетинг: методические основы и практические направления применения в бизнесе // Маркетинг в России и за рубежом. № 3. С. 13-18.Radygina E.G. (2019). Internet as space to marketing communication. Gosudarstvennyy sovetnik / The State Counsellor, no. 3, pp. 109–115. (in Russ.)Радыгина Е.Г. (2019). Интернет как пространство маркетинговой коммуникации // Государственный советник. № 3. С. 109-115.Starovoyt M.V. (2015). Aspects of communicative and consumer behaviour of modern internet users. Vestnik Severnogo (Arkticheskogo) federalnogo universiteta. Seriya: Gumanitarnye i sotsialnye nauki / Vestnik of Northern (Arctic) Federal University. Series: Humanitarian and Social Sciences, no. 3, pp. 63–70. (in Russ.)Старовойт М.В. (2015). Особенности потребительского и коммуникативного поведения современных пользователей Интернета // Вестник Северного (Арктического) федерального университета. Серия: Гуманитарные и социальные науки. № 3. С. 63-70.Sterligova A.N. (2003). Inventory management of a wide range of stock: Where to start? Loginfo, no. 12, pp. 50–55. (in Russ.)Стерлигова А.Н. (2003). Управление запасами широкой номенклатуры: с чего начать? // Логинфо. № 1. С. 46-51.Udalykh E.A. (2016). ABC analysis as an effective inventory management control system at an enterprise. Vestnik magistratury / Bulletin of the Magistracy, vol. 3, no. 1 (52), pp. 65–67. (in Russ.)Удалых Е.А. (2016). АВС-анализ как эффективная система контроля управления запасами на предприятии // Вестник магистратуры. Т. 3, № 1 (52). С. 65-67.Yarosh O.B., Kalkova N.N., Mitina E.A. (2023). Information asymmetry in trade: Neuromarketing methods and algorithms. Simferopol: ARIAL Publ. (in Russ.)Ярош О.Б., Калькова Н.Н., Митина Э.А. (2023). Информационная асимметрия: методы и алгоритмы нейромаркетинга. Симферополь: АРИАЛ.Bruner G.C. II, Kumar A. (2000). Web commercials and advertising hierarchy-of-effects. Journal of Advertising Research, vol. 40, issue 1-2, рр. 35-42. https://doi.org/10.2501/jar-40-1-2-35-42Bruner G.C. II, Kumar A. (2000). Web commercials and advertising hierarchy-of-effects. Journal of Advertising Research, vol. 40, issue 1-2, рр. 35-42. https://doi.org/10.2501/jar-40-1-2-35-42Duchowski A. (2007). Eye tracking methodology: Theory and practice. London: Springer. https://doi.org/10.1007/978-1-84628-609-4Duchowski A. (2007). Eye tracking methodology: Theory and practice. London: Springer. https://doi.org/10.1007/978-1-84628-609-4Harezlak K., Kasprowski P., Stasch M. (2014). Towards accurate eye tracker calibration - Methods and procedures. Procedia Computer Science, vol. 35, pp. 1073-1081. https://doi.org/10.1016/j.procs.2014.08.194Harezlak K., Kasprowski P., Stasch M. (2014). Towards accurate eye tracker calibration - Methods and procedures. Procedia Computer Science, vol. 35, pp. 1073-1081. https://doi.org/10.1016/j.procs.2014.08.194Huddleston P.T., Behe B.K., Driesener C., Minahan S. (2018). Inside-outside: Using eye-tracking to investigate search-choice processes in the retail environment. Journal of Retailing and Consumer Services, vol. 43, pp. 85-93. https://doi.org/10.1016/j.jretconser.2018.03.006Huddleston P.T., Behe B.K., Driesener C., Minahan S. (2018). Inside-outside: Using eye-tracking to investigate search-choice processes in the retail environment. Journal of Retailing and Consumer Services, vol. 43, pp. 85-93. https://doi.org/10.1016/j.jretconser.2018.03.006Husić-Mehmedović M., Omeragić I., Batagelj Z., Kolar T. (2017). Seeing is not necessarily liking: Advancing research on package design with eye-tracking. Journal of Business Research, vol. 80, pp. 145-154. https://doi.org/10.1016/j.jbusres.2017.04.019Husić-Mehmedović M., Omeragić I., Batagelj Z., Kolar T. (2017). Seeing is not necessarily liking: Advancing research on package design with eye-tracking. Journal of Business Research, vol. 80, pp. 145-154. https://doi.org/10.1016/j.jbusres.2017.04.019Intons-Peterson M.J., Roskos-Ewoldsen B.B. (1989). Sensory-perception quality of images. Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 15, no. 2, рр. 188-199. https://doi.org/10.1037//0278-7393.15.2.188Intons-Peterson M.J., Roskos-Ewoldsen B.B. (1989). Sensory-perception quality of images. Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 15, no. 2, рр. 188-199. https://doi.org/10.1037//0278-7393.15.2.188Just M.A., Carpenter P.A. (1980). A theory of reading: From eye fixations to comprehension. Psychological Review, vol. 87, no. 4, pp. 329-354. https://doi.org/10.1037/0033-295X.87.4.329Just M.A., Carpenter P.A. (1980). A theory of reading: From eye fixations to comprehension. Psychological Review, vol. 87, no. 4, pp. 329-354. https://doi.org/10.1037/0033-295X.87.4.329Kahneman D., Knetsch J.L., Thaler R.H. (1990). Experimental tests of the endowment effect and the Coase theorem. Journal of Political Economy, vol. 98, no. 6, рр. 1325-1348. https://doi.org/10.1086/261737Kahneman D., Knetsch J.L., Thaler R.H. (1990). Experimental tests of the endowment effect and the Coase theorem. Journal of Political Economy, vol. 98, no. 6, рр. 1325-1348. https://doi.org/10.1086/261737Karson E.J., Fisher R.J. (2005). Predicting intentions to return to the web site: Extending the dual mediation hypothesis. Journal of Interactive Marketing, vol. 19, issue 3, рр. 2-14. https://doi.org/10.1002/dir.20040Karson E.J., Fisher R.J. (2005). Predicting intentions to return to the web site: Extending the dual mediation hypothesis. Journal of Interactive Marketing, vol. 19, issue 3, рр. 2-14. https://doi.org/10.1002/dir.20040MacInnis D.J., Price L.L. (1987). The role of imagery in information processing: Review and extensions. Journal of Consumer Research, vol. 13, issue 4, рр. 473-491. https://doi.org/10.1086/209082MacInnis D.J., Price L.L. (1987). The role of imagery in information processing: Review and extensions. Journal of Consumer Research, vol. 13, issue 4, рр. 473-491. https://doi.org/10.1086/209082Mohammed R., Fisher R.J., Jaworski B.J., Cahill A. (2001). Internet marketing: Building advantage in a networked economy. New York: McGraw-Hill.Mohammed R., Fisher R.J., Jaworski B.J., Cahill A. (2001). Internet marketing: Building advantage in a networked economy. New York: McGraw-Hill.Naknil P., Chansom N. (2023). Electronic commerce (e-commerce) to increase the efficiency of managing small and medium enterprises (SME) in production of Pathum Thani province. Mahachula Academic Journal, vol. 10, no. 2, pp. 256-268. (in Thai)Naknil P., Chansom N. (2023). Electronic commerce (e-commerce) to increase the efficiency of managing small and medium enterprises (SME) in production of Pathum Thani province. Mahachula Academic Journal, vol. 10, no. 2, pp. 256-268. (in Thai)Nordfält J., Ahlbom C.-P. (2024). Utilising eye-tracking data in retailing field research: A practical guide. Journal of Retailing, vol. 100, issue 1, pp. 148-160. https://doi.org/10.1016/j.jretai.2024.02.005Nordfält J., Ahlbom C.-P. (2024). Utilising eye-tracking data in retailing field research: A practical guide. Journal of Retailing, vol. 100, issue 1, pp. 148-160. https://doi.org/10.1016/j.jretai.2024.02.005Orquin J.L., Holmqvist K. (2018). Threats to the validity of eye-movement research in psychology. Behavior Research Methods, vol. 50, no. 4, рр. 1645-1656. https://doi.org/10.3758/s13428-017-0998-zOrquin J.L., Holmqvist K. (2018). Threats to the validity of eye-movement research in psychology. Behavior Research Methods, vol. 50, no. 4, рр. 1645-1656. https://doi.org/10.3758/s13428-017-0998-zPeck J., Shu S.B. (2009). The effect of mere touch on perceived ownership. Journal of Consumer Research, vol. 36, issue 3, рр. 434-447. https://doi.org/10.1086/598614Peck J., Shu S.B. (2009). The effect of mere touch on perceived ownership. Journal of Consumer Research, vol. 36, issue 3, рр. 434-447. https://doi.org/10.1086/598614Shu S.B., Peck J. (2011). Perceived ownership and affective reaction: Emotional attachment process variables and the endowment effect. Journal of Consumer Psychology, vol. 21, issue 4, рр. 439-452. https://doi.org/10.1016/j.jcps.2011.01.002Shu S.B., Peck J. (2011). Perceived ownership and affective reaction: Emotional attachment process variables and the endowment effect. Journal of Consumer Psychology, vol. 21, issue 4, рр. 439-452. https://doi.org/10.1016/j.jcps.2011.01.002Verhoef P.C., Langerak F. (2001). Possible determinants of consumers' adoption of electronic grocery shopping in the Netherlands. Journal of Retailing and Consumer Services, vol. 8, issue 5, pp. 275-285. https://doi.org/10.1016/S0969-6989(00)00033-3Verhoef P.C., Langerak F. (2001). Possible determinants of consumers' adoption of electronic grocery shopping in the Netherlands. Journal of Retailing and Consumer Services, vol. 8, issue 5, pp. 275-285. https://doi.org/10.1016/S0969-6989(00)00033-3Akulich M.V. (2016). Internet marketing. Moscow: Dashkov i Ko Publ. (in Russ.)Ivashkin M.V., Kolesnikov A.V., Otteva I.V. (2022). Internet merchandising: Concept and specifics of use in modern retail. Gumanitarnye, sotsialno-ekonomicheskie i obshchestvennye nauki / Humanities, Social-Economic and Social Sciences, no. 12-1, pp. 130–135. https://doi.org/10.17150/2500-2759.2020. (in Russ.)Kalkova N.N., Yarosh O.B., Kalkov D.A. (2024). Computer program “Estimation of probability of consumer choice of goods in online environment by ABC-analysis method based on visual neuromarketing data”. Copyright certificate of the state registration of the computer program no. RU2024617947. Simferopol: V.I. Vernadsky Crimean Federal University. (in Russ.)Kalkova N.N., Yarosh O.B. (2024a). Database for estimating the probability of consumer choice of cheese in online environment by ABC analysis based on visual neuromarketing metrics with low density of placed goods. Copyright certificate of the state registration of the database no. RU2024621472. Simferopol: V.I. Vernadsky Crimean Federal University. (in Russ.)Kalkova N.N., Yarosh O.B. (2024b). Database for estimating the probability of consumer choice of cheese in online environment by ABC analysis based on visual neuromarketing metrics with medium density of placed goods. Copyright certificate of the state registration of the database no. RU2024621473. Simferopol: V.I. Vernadsky Crimean Federal University. (in Russ.)Kalkova N.N., Yarosh O.B. (2024c). Database for estimating the probability of consumer choice of cheese in online environment by ABC analysis based on visual neuromarketing metrics with high density of placed goods. Copyright certificate of the state registration of the database no. RU2024621574. Simferopol: V.I. Vernadsky Crimean Federal University. (in Russ.)Kazanskaya I.V., Yamshchikov S.V., Romashkina A.P. (2022). Consumption and consumer behavior in the digital age. Gumanitarnye, sotsialno-ekonomicheskie i obshchestvennye nauki / Humanities, Social-Economic and Social Sciences, no. 1, pp. 43–47. https://doi.org/10.23672/t1024-0645-1658-b. (in Russ.)Kerzina E.A. (2019). Neuromarketing: Methodological foundations and practical directions of application in business. Marketing v Rossii i za rubezhom / Marketing in Russia and Abroad, no. 3, pp. 13–18. (in Russ.)Radygina E.G. (2019). Internet as space to marketing communication. Gosudarstvennyy sovetnik / The State Counsellor, no. 3, pp. 109–115. (in Russ.)Starovoyt M.V. (2015). Aspects of communicative and consumer behaviour of modern internet users. Vestnik Severnogo (Arkticheskogo) federalnogo universiteta. Seriya: Gumanitarnye i sotsialnye nauki / Vestnik of Northern (Arctic) Federal University. Series: Humanitarian and Social Sciences, no. 3, pp. 63–70. (in Russ.)Sterligova A.N. (2003). Inventory management of a wide range of stock: Where to start? Loginfo, no. 12, pp. 50–55. (in Russ.)Udalykh E.A. (2016). ABC analysis as an effective inventory management control system at an enterprise. Vestnik magistratury / Bulletin of the Magistracy, vol. 3, no. 1 (52), pp. 65–67. (in Russ.)Yarosh O.B., Kalkova N.N., Mitina E.A. (2023). Information asymmetry in trade: Neuromarketing methods and algorithms. Simferopol: ARIAL Publ. (in Russ.)Bruner G.C. II, Kumar A. (2000). Web commercials and advertising hierarchy-of-effects. Journal of Advertising Research, vol. 40, issue 1-2, рр. 35-42. https://doi.org/10.2501/jar-40-1-2-35-42Duchowski A. (2007). Eye tracking methodology: Theory and practice. London: Springer. https://doi.org/10.1007/978-1-84628-609-4Harezlak K., Kasprowski P., Stasch M. (2014). Towards accurate eye tracker calibration - Methods and procedures. Procedia Computer Science, vol. 35, pp. 1073-1081. https://doi.org/10.1016/j.procs.2014.08.194Huddleston P.T., Behe B.K., Driesener C., Minahan S. (2018). Inside-outside: Using eye-tracking to investigate search-choice processes in the retail environment. Journal of Retailing and Consumer Services, vol. 43, pp. 85-93. https://doi.org/10.1016/j.jretconser.2018.03.006Husić-Mehmedović M., Omeragić I., Batagelj Z., Kolar T. (2017). Seeing is not necessarily liking: Advancing research on package design with eye-tracking. Journal of Business Research, vol. 80, pp. 145-154. https://doi.org/10.1016/j.jbusres.2017.04.019Intons-Peterson M.J., Roskos-Ewoldsen B.B. (1989). Sensory-perception quality of images. Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 15, no. 2, рр. 188-199. https://doi.org/10.1037//0278-7393.15.2.188Just M.A., Carpenter P.A. (1980). A theory of reading: From eye fixations to comprehension. Psychological Review, vol. 87, no. 4, pp. 329-354. https://doi.org/10.1037/0033-295X.87.4.329Kahneman D., Knetsch J.L., Thaler R.H. (1990). Experimental tests of the endowment effect and the Coase theorem. Journal of Political Economy, vol. 98, no. 6, рр. 1325-1348. https://doi.org/10.1086/261737Karson E.J., Fisher R.J. (2005). Predicting intentions to return to the web site: Extending the dual mediation hypothesis. Journal of Interactive Marketing, vol. 19, issue 3, рр. 2-14. https://doi.org/10.1002/dir.20040MacInnis D.J., Price L.L. (1987). The role of imagery in information processing: Review and extensions. Journal of Consumer Research, vol. 13, issue 4, рр. 473-491. https://doi.org/10.1086/209082Mohammed R., Fisher R.J., Jaworski B.J., Cahill A. (2001). Internet marketing: Building advantage in a networked economy. New York: McGraw-Hill.Naknil P., Chansom N. (2023). Electronic commerce (e-commerce) to increase the efficiency of managing small and medium enterprises (SME) in production of Pathum Thani province. Mahachula Academic Journal, vol. 10, no. 2, pp. 256-268. (in Thai)Nordfält J., Ahlbom C.-P. (2024). Utilising eye-tracking data in retailing field research: A practical guide. Journal of Retailing, vol. 100, issue 1, pp. 148-160. https://doi.org/10.1016/j.jretai.2024.02.005Orquin J.L., Holmqvist K. (2018). Threats to the validity of eye-movement research in psychology. Behavior Research Methods, vol. 50, no. 4, рр. 1645-1656. https://doi.org/10.3758/s13428-017-0998-zPeck J., Shu S.B. (2009). The effect of mere touch on perceived ownership. Journal of Consumer Research, vol. 36, issue 3, рр. 434-447. https://doi.org/10.1086/598614Shu S.B., Peck J. (2011). Perceived ownership and affective reaction: Emotional attachment process variables and the endowment effect. Journal of Consumer Psychology, vol. 21, issue 4, рр. 439-452. https://doi.org/10.1016/j.jcps.2011.01.002Verhoef P.C., Langerak F. (2001). Possible determinants of consumers' adoption of electronic grocery shopping in the Netherlands. Journal of Retailing and Consumer Services, vol. 8, issue 5, pp. 275-285. https://doi.org/10.1016/S0969-6989(00)00033-3