CAL stand for Computer Aided Learning and in many cases referred to as Computer Aided Instruction as well [Bachman, 1998].
An in depth review of the literature suggests that there is no concrete definition of CAL as such. Many researchers have explained what can be achieved by CAL and how it can be done but no one has really tried to define CAL. Computer Aided Learning in simple terms can be described as an aid or assistance towards the learning process using a computer. It is very important to note here that we are using the word ‘aid’. Here ‘aid’ is important because while using computers in the learning process no attempt is being made to replace the teacher or lecturer and the computer is used as an aid only. Computer aided Learning has been promoted in a number of ways for teaching and learning purpose. Some of these include Problem Based Learning [Schor et al, 1995], teaching basic anatomy [Stanford et al, 1994], supplementing lectures and tutorials [Shannon, 1990] etc. It is important to note that CAL should not be considered as a single program or application that fulfils a certain task as desired by the user. CAL can be a single or series of programs or application which acts as an aid to the overall learning process.

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Historically, it was in the early fifties during the last century that human beings used any kind of electronic device to perform a mathematical calculation. As soon as this was realized a series of developments took place and soon the computer came into being. People realized the immense potential computers had and started to use it in almost every field. Researchers openly stated that the use of computer for educational purpose would change the face of education in a very short span of time. Schittek (2001) points out that it was not until august 1981, when IBM presented the microcomputer IBM PC (personal computer) that the use of computers for educational purpose started to develop. Researchers like Papert (1994) then suggested the use of classroom computers and abandon the worksheet curriculum. As a common belief the researchers in favor of CAL believed that computer had the potential to stimulate and support various educational goals. The crucial question at that time and even now is that which goal/s should be selected? It was very important to select the goals appropriately as the choices made would have an immense effect on the children’s minds, their learning styles and on the education process overall. The educational goals that could be achieved using computers 20 years back were limited due to technological barriers. With an exponential growth in technological breakthroughs and growing experience in using these computers for education the statements made during the last quarter of the 19th century makes a lot of sense now. Technology is no more a barrier today and it is up to the academicians to use it appropriately to meet the desired educational goals.There were many detractors for the use of computers in education as well. One of the primary reservations was the concept that computers will eventually replace the traditional teacher or lecturer. Other reasons include the reluctance to change their mindset to accommodate something new in the curriculum. These researchers felt that computers were a challenge to the existent educational practices at the intellectual, social, economic and pragmatic levels and hence favored the traditional methods over the use of computers. The supporters of CAL argue that we never questioned the fact that blackboard or books will replace the teacher then why are we so opposed to the use of computers in education? Even today these groups of people are outnumbered by the detractors and are continuing their effort to justify the numerous advantages that computers can bring in to the educational curriculum. This is even more evident from the fact that there are today a number of CAL programs available on the market, However it seems that the development of CAL is based on the work of very few individuals rather than being a part of the faculty’s ICT strategies [Plasschaert et al, 1995]
1. Game-based learning: Generally, games satisfy the basic requirements of learning environments identified by Norman (1993) and can provide an engaging environment for learning. Games should provide possibilities for reflectively exploring phenomena, testing hypotheses and constructing objects.2. Computer simulations: Grimes et al.(1988) studied the effects of a textbook-based software package in two classes of the Introductory Macroeconomics course. Their results indicate no statistically significant difference in learning between the experimental (software users) and control (non-users) groups. Finally, Grimes and Wiley (1990) conducted an experiment using a textbook-based simulation package in the Introductory Macroeconomics course. Their results indicate a statistically significant difference in overall attitude and performance between students who did and did not use the simulation software.3. Animations: One particularly promising capability of computer based learning is the ability to integrate animation as part of instruction. Authoring application programs have made animation readily accessible to any educator who has the patience to learn how to use the application (Sturman, 1998).Some other forms of Computer based instruction include Virtual Seminars/ Video conferencing, Drill and Practice and Problem Solving.
The role of CAL in education is recognized and appreciated by more and more people as time passes by. CAL has taken several forms depending on the available technology available as described earlier. Hence its role in education has also varied over time. In its infancy CAL was used as a knowledge bank of questions and the students could self-assess themselves. Apart from this other computer related activities were not really adding to the ‘learning’ process of the students. With the advent of multimedia the role of CAL was extended and it was used to display simulations and animations to the students which were otherwise not possible for the students too see in real-time. This was seen as one of the most important reason to include computers in the classroom lecture as far as the teachers were concerned. Apart from this the teachers and the lecturers are generally very reluctant to incorporate CAL due to several reasons as discussed by Heywood and Norman (1988). First of all they feel that the available software does not match their exact criteria to meet specific curriculum goals. Secondly it is very time consuming process for them to learn the technology first and then convert the existing material they have in CAL format. Heywood and Norman (1988) found that the second factor was not a result of added workload but was more due to the confidence in their own abilities in the use of the technology. This essentially means that while the government is actively promoting the use of CAL in the curriculum it should also lay the guideline on how to do it and train the educators in the first instance.There is little doubt about the growing importance of CAL in education as research shows that CAL can have positive influence on the student learning [Devitt and Palmer, 1998]. Devitt further added that providing study material in computer format can improve knowledge on the subject. Ideally the role of CAL in education lies in the hands of the academicians. The role that these Educators give to CAL will determine the limits of its achievement.
What makes a successful CAL?Some of the main pedagogical and economical forces that have driven the push for universities and schools to adopt and incorporate computer aided learning include:Greater information access – The World Wide Web has made it possible for people to access primary sources of information on demand. Mastery of this tool has become essential in order to gain access to an ever-growing body of recent and up-to-date knowledge available electronically.Greater Communication facilities – Interaction between academic staff, colleagues and students can be structured and managed through electronic communications to provide greater access and flexibility (Bates 2000)The quality of teaching – New technologies have gained much attention from academic staff as they perceive their use will lessen their problems of high workloads, increased student to teacher ratio and use of inexperienced staff to teach (Bates 2000). There is ample evidence that well designed multimedia software can be more effective than traditional classroom methods, where students are able to interact with the software and learn at their own pace. Integrated effectively into the classroom environment, ICTs can facilitate higher order thinking skills and develop new ways of learning (Barron & Ivers, 1996; Bates, 2000)Asynchronous learning – This initiative has enabled institutions to cater for a variety of students by removing the barriers of time and distance. Students who are normally geographically disadvantaged have access to a variety of resources not usually at their disposal (McNaught et al., 1999; Bates, 2000).Pedagogical Improvement and staff renewal – Teaching staff are able to preset information using a variety of tools in order to better relate to the content to the concrete realities of a given field of study. Innovative hands-on learning experiences are also made possible for students through computer simulation software.
Advantages of CALOne of the main advantages of Computer aided learning concerns the time, the place and the pace with which one can learn. A few more advantages of CAL identified by other researchers and authors are listed below:1. Provision of alternative teaching techniques. The computer can utilize a number of teaching methods and materials that may not be viable to use in a traditional setting. For example, a graphics display terminal using animated characters on a screen is a stimulating tool [Deaton, 1991].2. Individualized instruction. Learning is significantly more effective and efficient when instruction can be tailored to the unique needs of each learner. CAL enables students to go through specific lessons at their own pace [Semb et al, 1991].3. Ability to conduct simulations. In a national survey on the use of CAL in Dutch institutions of higher education, de Jong et al (1992) found that the most popular form of CAL was simulation. One of the reasons that simulation is so popular could be that it is the only type of CAL in which the program adds something to the curriculum that a teacher cannot offer.4. Providing instructions on demand. The computer can provide virtually unlimited accessibility to educational material. The computer’s availability is not constrained by the same factors that place a limit on a teacher’s time. Whereas a teacher is available only during specific hours, in a specific place, and usually for group lessons, a computer is available for use at all times and on an individual basis and in many places [Stern and Stern, 1983; Telfer and Probert, 1986].5. Flexibility is another reported strength of CAL (Petrides, 2002; Schrum, 2002). Petrides (2002) stated that participants reported it was easier to work in collaborative groups in an online course without rearranging everyone’s schedule as one might do in a traditional face-to-face course.In a study conducted by Coyner and McCann (2004), learner’s feedback on four courses was taken and different advantages and challenges associated with learning and teaching online were noted. Computer-aided learning can be considered as a part of online learning. The acronym ACCOMMODATE signifies the advantages identified (Coyner and McCann, 2004).A – Accessibility. Computer aided learning provides the students with access to the material 24 hours a day.C -Convenience. Students can work and study according to their own time schedule and their convenience.C – Critical Thinking. Critical thinking techniques are enhanced as the students have the associated data and information available to them 24 hours a day.O – Offers. Students are aware of all the components of the course and they can compare themselves with others.M – Model. Future use can be enhanced with CAL.O – Organization. Course can be organized much before the starting of the particular course.D – Dependence. All the necessary resources are available to the students and sot he dependence on the teachers is decreased.A – Accountability. Any online course provides a lot of information about the users and so the student’s accountability can be checked easily.T- Technology. Students acquire good technological skills.E – Encourages. Students can work in teams and it encourages more participation.
Some people feel that if students spend the bulk of their time interacting with a terminal, rather than with people, they can lose touch with what others are doing and feel isolated and alienated [Telfer and Probert, 1986; Chambers and Sprecher, 1990]. Even though the costs of hardware and software have significantly decreased in the last few years, an extensive capital investment is still required for implementing and using CAL [Shlechter, 1991]. The results of several studies have shown that teachers lack time to get to know CAL programs [Cox et al, 1988], prepare and integrate CAL [D’Amico, 1990], develop software, and set up or maintain equipment [Hammond et al, 1992]. Inadequate training of teachers has contributed to a lack of computer use. Training should not be about computer or technology alone but about how computers can help in teaching the subject matter [Brancum, 1992]. A survey conducted by Plomp et al (1990) revealed that the resistance of teachers against computers was a constraining factor to implementing CAL. Participants in Hara and Kling’s (1999) qualitative case study of a Web-based course at a major U.S. university reported lack of immediacy in getting responses back from the instructor, and as a result they felt frustrated. Recent studies indicate similar results. For example, in Vonderwell’s (2003) study, one reported disadvantage of an online course was the delay of immediate feedback from the instructor.
Comparison of traditional learning skills and CAL skills
What traditional classroom learning achieves: The teaching strategy that has been used for centuries is lecturing – an expert telling the students what they should know. A teacher’s personal enthusiasm for a subject can be transmitted through non-verbal behaviors such as eye contact with students, voice projection, body language and story telling (Stephenson, 2001). The physical presence of the lecturer in the classroom creates a sense of responsibility to the students towards the subject and they can be provoked and stimulated by observing an expert teaching and demonstrating them. One of the major advantages of lectures is that the learners can get response to their queries there and then. While in Online learning this is not the case. Some studies have shown that students complain about the workload required by self-study in the Web-based instruction (Nachmias et al, 2000).
What Computer-Aided Learning achieves – Generally classroom teaching has a high teacher-to-learner ratio which leads to less interaction between teacher and learner. One to one relationship is emphasized more in Online learning than in classroom lectures. According to Tiffin & Rajasingham (1995), the traditional classroom teaching means that besides organizing a place for learning, it is necessary to organize when teachers and learners meet and how they use their time. Typically, classroom instruction provides a set group of students with a set chunk of instruction on set sates for set period of time. Here one can visualize the importance of online learning by comparing the efficiency of this scenario with providing the information the individual learner wants, when the learner wants, at the pace the learner wants, for the length of time and with the frequency that suits the learner. In a study conducted at the University of Akron (Coyner & McCann, 2004), several advantages of conducting an online course were analyzed. According to their study, the learners can access the online course information at any time of the day and they can work at times/locations convenient to their lifestyle. They are no longer instructor dependent for information, resources and materials. Emphasis on threaded discussions, chats and forums encouraged learners to work together. According to a study on improving online learning (Song et al, 2004), participants reported that it was helpful not to have to travel to the campus. The ability to complete assignments and tasks at anytime was another reported strength. The benefits of CAL are many including cost-effectiveness, enhanced responsiveness to change, consistency, timely content, flexible accessibility, and providing customer value (Rosenberg, 2001). Most of the studies on the assessment of students’ attitudes towards online computer-aided instruction have concluded that such courses compare favorably with classroom-based instruction and enjoy high student satisfaction (Phipps & Merisotis, 1999). Also some potential value can be added to online learning by providing the opportunity for guest experts from around the world to share and contribute to a class by posting excerpts of articles, statements and so on (Paulsen, 1995).
According to a study conducted by Ross and Schulz (1999), it was concluded that computer aided instruction is not suitable for all learners. Studies show that some learners have difficulty adapting to computer aided learning. Hoffman and Water (1982) stated that computer aided learning is suited for individuals who have the ability to quietly concentrate, are able to pay attention to details and have an affinity to memorizing details. According to Gregorc (1985), a computer cannot represent a teacher who may be able to troubleshoot and modify the lesson according to the student’s needs. He adds that “students who cannot meet the demands of the system are denied access to the content and goals and are vulnerable to possible psychological damage. Children can therefore become victims of a medium which is offensive to them. They are at the mercy of the machine.” Also Regular lecture meetings provide structure to the working day, and some implicit information about the rate at which factual material can reasonably be covered and assimilated.Advocates of CAL claim it gives students control over when and where they learn and the pace of their learning (Smart, 1997; Adnanes & Ronning, 1998). One of the main features of computer-aided Learning is its capacity to individualise instruction to meet the specific needs of the learner (Rasmussen and Davidson, 1996). According to a study conducted by Dewhurst et al (2000), Students moved more towards agreeing with the proposition that the Computer aided learning would allow them to work at their own pace, perhaps favouring their own particular learning style, and that it offered greater flexibility, enabling them to choose where and when they studied. CAL constitutes an appropriate and acceptable alternative to conventional classroom learning and the students having little previous practical experience with such learning and study approach can appropriate it readily.Whether CAL is better than traditional classroom learning is a debatable question. According to a study conducted by Tjaden and Martin (1995), it is important to get direction from and interact with an instructor for introductions to topics and question-answer periods. But some phases of the learning process could be carried out more efficiently, at least time wise, with the aid of a computer program, whether it be hypermedia, multimedia or simpler tutorials. Many studies have shown that many students retain a preference for a `mixed economy’ in which the CAL plays a part alongside more conventional approaches. This is called Blended Learning which is discussed in detail in the next section.
A variety of teaching methods exist in this society, (lectures, audiotapes, purely online, a mixture of both online and traditional classroom teaching) and it may be possible that student’s choice of the best teaching method varies with their personality differences. In such a case, the teachers should use a variety of methods to cater for the differences between the students. This is not easy but it is one of the strong reasons of supporting a mixture of both computer-based and traditional classroom teaching. There is no doubt that the physical environment has a surprisingly powerful influence on teaching. But, sometimes, lectures are relatively ineffective to inspire interest in a subject and are relatively ineffective for personal and social adjustment (Bligh, 1998). Thus, it has given way to blended environment in which the large lecture theatres are equipped with networked computers through which vast range of digitized information can be accessed. Even online learning environment is just another physical environment with more complexity and with more use of technology. But learners are not able to accept this environment fully because apart from making possible some kinds of activities like one to one communication with many different people it also restricts some activities like spontaneous spoken conversation.At its simplest, blended learning is the integration of traditional classroom face-to-face teaching with online computer based teaching. At the same time, there is considerable complexity in its implementation with the challenge of virtually limitless design possibilities and applicability to so many contexts (Garrison & Kanuka, 2004). Rosenberg (2001) emphasizes that people learn more effectively when they interact and are involved with other people participating in similar endeavors. CAL is powerful when both training and knowledge management are integrated, but even more powerful when integrated with classroom training in a ”learning architecture” (p. 117). He defines a learning architecture as ”the design, sequencing, and integration of all electronic and non-electronic components of learning to derive optimum improvement in competence and performance”. Cross (2000) reports ‘the learning process breaks down when untouched by human hands. CAL is not training by robot.’
Till now we have discussed about the existing technologies and its application related to CAL and how they are affecting or changing the process of education in general. In order to predict the future of CAL we need to look back at the past with two different view points, namely technological and educational. As far as technology is concerned, it is far ahead of the educational developments in terms of pedagogy. Today technology is talking in terms of virtual Universities and will soon be ready for deployment but development in educational policy to incorporate such technology is moving at a snail’s pace. There are many institutions that still use computers in education because they are supposed to do so as per the national curriculum. This by no means is of any help for the future of CAL and education in general. This can be primarily attributed to the difference of opinion that still exists between the educators in the use of CAL.The author of this report feels that technology is at a point where it can deliver most of the educational requirements but the problem lies in the educational process. Presently CAL is undergoing a transition from the ‘acceptable’ state to the ‘accepted’ state. In order to be referred as widely accepted and successful in the future, CAL has to be actively incorporated and effectively used in the curriculum to benefit and enhance the overall learning process.
In February 2004, HEFCE (Higher Education funding Council for England) commissioned Glenaffric Ltd e-Learning consultants to undertake an initial analysis of the responses to consultation on the HEFCE (2004) e-learning strategy and produce a summary report. This report says: “There is an overwhelming request for the strategy to emphasize blended learning approaches rather than wholly e-based learning, as this remains the most appropriate use of technology for learning in campus-based institutions. However, one response urges caution about the assumption that the currently fashionable term ‘blended learning’ will be a long term concept of any value.” There is still much debate about whether wholly computer aided learning will replace blended learning. Cross (2000) notes that ‘the magic is in the mix’ but blended learning still has some aspects of traditional classroom learning which is often viewed as old fashioned, static and expensive to deliver.This research and discussion shows that not only is CAL of benefit to the students, but it can be used as a vital source of feedback to the lecturers if they are willing to accept it. Also CAL programs can be modified to provide greater assistance in the understanding of particular problems. CAL will definitely form an integral part of the education process in the future.
Adnanes, M., & Ronning, W. M. (1998). Computer-networks in education Ð a better way to learn? J. Computer. Assisted Learning, 14, 148 – 157.Bachman, M. W. Lua, M. J. Clay, D. J. Rudney, J. D. (1998) Comparing traditional lecture vs. computer-based instruction for oral anatomy. J Dent Educ 1998: 8: 587-591.Barron, A., & Ivers, K. (1996, June). An Internet Research Model. National Educational Computing Conference, Minneapolis, MN.Bates, A. W. (2000). Managing technological change: Strategies for college and university leaders. San Francisco: Jossey-Bass PublishersBrancum D., Educators used support to make computing meaningful. Macworld September, 83-88 (1992).Chambers J. A. and Sprecher J. W., Computer-assisted instruction: current trends and critical issues. Commun. /I CM. 23, 332 342 (1990).Cox M., Rhodes V. and Hall J., The use of computer-assisted learning in primary schools: some factors affecting the uptake. Computers Educ. 12, 173-178 (1988).Coyner, S. & McCann P.L. (2004). Advantages and challenges of teaching in an electronic environment: the accommodate Model. International Journal of Instructional Media. 31(3)Coyner, S. C and McCann, P. L. (2004). Advantages and challenges of teaching in an electronic environment: the accommodate model. International Journal of Instructional Media.D’Amico J. J., Three lessons I learned from a year of computer-based instruction. J. Comput.-based Instruct. 17, 103 109 (1990).de Jong T. et al., Computer-assisted learning in higher education in the Netherlands: a review of findings. Computers Educ. 19, 381-386 (1992).Deaton W. L. CBT and high education: issues, barriers and solutions. In Problems and Promises of Computer-based Training (Edited by Shlechter T. M.), pp. 215-231. Ablex, Norwood, N.J. (1991).Dewhurst, D. G., H. A. Macleod and T. A. M. Norris (2000). Independent student learning aided by computers: an acceptable alternative to lectures? Computers & Education 35(3): 223-241.Gregorc, A. (1985). Inside Styles Beyond the Basics. Columbia, CT: Gregorc Associates.Grimes P. W., Krehbiel T. L. and Ray M. A., Microcomputer tutorials and student learning in the principles of economics course: an empirical experiment. Coffegiarr Microcompurer 6, 247-252 (1988).Grimes P. W. and Wiley T. E., The effectiveness of microcomputer simulations in the principles of economics course.Computers Educ. 14, 81-86 (1990).Hammond et al., Blocks to the effective use of information technology in higher education. Computers Edue. lg, 155-162 (1992).Hara, N., & Kling, R. (1999). Students’ frustrations with a web-based distance education course. First Monday, 4(12). http://www.firstmonday.dk/issues/issue4_12/index.htmlHara, N., & Kling, R. (2000). Students’ distress with a web-based distance education course. Information, Communication & Society 3(4): 557-579. [Online]Available at: http://www.slis.indiana.edu/CSI/WP/wp00-01B.htmlHeywood, G. & Norman, P. (1988) Problems of educational innovation: the primary teacher’s response to using microcomputers, Journal of Computer Assisted Learning, 4, pp. 34-43Hoffman, J. L., & Waters, K.(1982).Some effects of student personality on success with computer-assisted instruction.Educational Technology, 22(3),20-21.Nachmias, R., Mioduser, D., Oren, A., & Ram, J. (2000). Web-supported emergent collaboration in higher education courses. Educational Technology and Society, 3(3), 94-104.Norman, D. A. (1993). Things that make us smart: Defending human attributes in the age of the machine. Reading, MA: Addison-Wesley Publishing Co.Papert, S. (1994) The Children’s Machine: rethinking school in the age of the computer. London: Harvester WheatsheafPaulsen, M. F., (1995). The online report on pedagogical techniques for computer-mediated communication. Available at: http://www.hs.nki.no/~morten/cmcped.htm#bPetrides, L.A. (2002). Web-based technologies for distributed (or distance) learning: Creating learning-centered educational experiences in the higher education classroom. International Journal of Instructional Media, 29(1), 69-77.Phipps, R., & Merisotis, J. (1999). What’s the difference? A review of contemporary research on the effectiveness of distance learning in higher education. Washington, DC: Institute for Higher Education Policy [On-line]. Available at: http://www.ihep.org/Pubs/PDF/Difference.pdfPlasschaert, A. J. Wilson, N. H. Cailleteau, J. G. Verdonschot, E. H.Opinions and experiences of dental students and faculty concerning computer-assisted learning. J Dent Educ 1995: 5:1034-1040.Plomp T., Pelgrum W. J. and Steerneman H. M., Influence of computer use on schools’ curriculum: limited integration. Computers Educ. 14, 159-171 (1990).Rasmussen, K., & Davidson, G.V. (1996). Dimensions of learning styles and their influence on performance in hypermedia lessons. Proceedings of the World Conference on Educational Multimedia and Hypermedia, USA, 800.Rosenberg, M.J. (2001). E-Learning: strategies for delivering knowledge in the digital age. New York, NY: McGraw-Hill Companies.Ross, J. L. & Schulz, R. A. (1999). “Can computer-aided instruction accommodate all learners equally?” British Journal of Educational Technology, 30(1), 5-24.
Schittek M, Mattheos N, Lyon HC, Attstrom R. (2001) Computer assisted learning. A review. Eur J Dent Educ. 2001 Aug;5(3):93-100.
Schor, N. F. Troen P. Adler, S. Williams JG, Kanter SL, Mahling DE, Sorrows B, Skogseid I, Bernier GM Jr (1995) Integrated case studies and medical decision making: a novel, computer-assisted bridge from the basic sciences to the clinics. Acad Med. 1995 Sep;70(9):814-7.
Schrum, L. (2002). Oh, What wonders you will see: Distance education past, present, and future. Learning and Leading with Technology, 30(3), 6-9, 20-21.Semb G. B., Ellis J. A., Montague W. E. and Wulfeck W. H., Self-paced instruction: perceptions, pitfalls and potentials. In Problems and Promises of Computer-based Training (Edited by Shlechter T. M.t, pp. 119 -137. Ablex, Norwood, N,J. (1991).Shannon, J. D. (1990), Small-group interactive computer-assisted teaching, Med Educ. 1990 Mar;24(2):148-50.Shlechter T. M. (Ed.), Promises, promises, promises: history and foundation of CBT. In Prohh’ms and Promises of Computer-based Training, pp. 1 20. Ablex, Norwood, N.J. (1991).Smart, C. (1997). Educational implications of the web. Life Sciences Educational Computing, 8(1), 13 – 14 (Newsletter of the CTI Centre for Biology).Song, L., Singleton, E.S., Hill, J.R. & Koh, M.H. (2004). Improving online learning: Student perceptions of useful and challenging characteristics. Internet and Higher Education 7 (2004) 59-70Stanford, W. Erkonen, W. E. Cassell, M. D. Moran BD, Easley G, Carris RL, Albanese MA (1994) Evaluation of a computer-based program for teaching cardiac anatomy, Investigative Radiology 1994 Feb;29(2):248-52.Stephenson, J. (2001). Teaching & Learning Online – Pedagogies for new technologies. Stylus Publishing, Sterling, USA.Stern N. and Stern R. A., Computers in Society. Prentice-Hall, En