Volume 4, Number 1 - Fall 1995

© Logo Foundation

You may copy and distribute this document for educational purposes provided that you do not charge for such copies and that this copyright notice is reproduced in full.

These are the major articles that appeared in Logo Update, Volume 1, Number 4 - Fall 1995. Minor changes have been made to update information such as addresses. Conference announcements and other items of transient interest that appeared in the original newsletter have not been included here.

In this issue:

Logo as a Window into the Mind by José Armando Valente

The Turtle is Dead: Rethinking Logo in the Age of Kid Pix by Michael Tempel

The Case for Classic Logo by David L. McClees and Dorothy M. Fitch


Logo as a Window into the Mind

José Armando Valente

If we could "penetrate" into the student's mind to find misconceptions and bugs, we would be able to intervene more effectively to help the student to learn better. Even though this was desired by many teachers, the reason it wasn't done is that we did not have good ways of getting into the mind. We didn't until we had computers!

Computers have provided us with the possibility of penetrating into the learner's mind in ways that we never had before. Artificial Intelligence and Cognitive Science have benefited from this enormously. And in the Logo community, especially within the group working with handicapped children, it was common to hear that Logo provided us with a "window into the child's mind" (Weir, 1987). The argument was that a Logo program had imbedded in it the student's concepts, strategies, and styles, which could only be the product of his mind. Looking at students' programs we could have ways of understanding how their minds worked in the process of developing the programs, and the level of knowledge, strategies, and style used.
However, the current uses of computers in education and the educational software available have minimized programming activities. The emphasis of computer activities has been on the creation of finished products with minimal effort. It seems that this line of thinking undermines one of Logo's original objectives and dismisses important characteristics of the computer as a tool for enhancing learning.

Why Programming?
Any intellectual activity can be seen as a window into the mind. However, there are important features of programming that allow us to penetrate into one's mind that we did not have before.
The discussion about "why programming" is a current topic in the Logo literature. Seymour Papert presented several examples in which programming allows the computer user to have better control over the computer (Papert, 1993). The reason Papert prefers programming over ready-made educational software is that "discovery cannot be a setup; invention cannot be scheduled" (Papert, 1980, pp. 115). "Is Programming Obsolete?" (Clements and Meredith, 1993) gives a summary of an American Educational Research Association meeting in which several speakers presented different views of programming. Programming is "the best ever representational support for cognitive activities" according to Andrea diSessa. Mitchel Resnick is cited as describing programming "as an expressive medium." I certainly agree with these views but I think that programming should be placed into a theoretical framework along the lines of that proposed by Solomon (1982).
The window into the mind emerges when one considers the process of programming as a cycle consisting of description-execution-reflection-debugging-description (Valente, 1994). When a student is using Logo (I will concentrate, for the moment, on the graphics aspect of Logo) his initial ideas about how to solve the problem are passed to the computer (or the Turtle) in terms of Logo commands. Thus, the student is acting upon the object "computer." However, this action is also a description of the problem solution through the Logo procedures. The computer then executes these procedures. The Turtle "walks through" each instruction in each of the procedures and presents a result in terms of a picture on the screen. The student observes this process and the final product, and can reflect upon them. This reflective activity can lead to one of two alternative actions: doing nothing, when the student accepts the result presented by the computer and considers the problem solved; or debugging, when the result is different from what the student intended or the result is not accepted by the student. Debugging can be either in terms of concepts in the subject area (the student does not know about angles, for example) or about some convention in the Logo language, or about strategies (the student does not know how to apply a particular concept.)
The cycle "description-execution-reflection-debugging-description" allows us to understand the learning process a little better, and why programming can be an effective activity for learning. In this cycle, debugging constitutes a unique opportunity for the student to construct his knowledge; to learn about particular concepts involved in the problem solution, and/or about problem-solving strategies. However, the debugging activity is facilitated by the existence of the computer program: the student's description of his ideas in terms of a formal, precise, and simple language. Also, there is a direct correspondence between each command and the computer's action, as reflected by the Turtle's behavior.
It is important to say that the cycle, description-execution-reflection-debugging-description, is part of a programming activity in any computer language. However, Logo graphics has added some aesthetics to this process in terms of simplicity, structure, and feedback. Interaction between the student and the computer is simplified with the use of terms used in everyday conversation, making the description of spatial problems in synchrony with intuitive spatial knowledge. The ease in naming and defining procedures facilitates the problem-solving process. Turtle graphics enhances the feedback from the computer, which feeds the reflective process. All these features were introduced without compromising the computational power of Logo.
Thus, it was the Logo aesthetics that made Logo such an important tool to think about, and to foster, learning. It allowed us to understand about constructionism: the how, when, and what that makes the construction of knowledge possible. It has catalyzed investigations into "learning about learning" since the student in the process of looking for information is exercising his learning skills. And it has raised questions about "thinking about thinking" since the students can analyze their programs in terms of effectiveness of their ideas, strategies, and problem-solving styles.
However, we have learned that none of these phenomena will happen by just placing a student in front of a computer. The student-computer interaction needs to be mediated by a professional who knows about Logo ideas. Students are part of a social environment, comprised of their peers, their parents, the school, and even the community. These social elements provide ideas, information, and problems to be solved through the use of the computer.

Logo Aesthetics Can Transcend Logo Graphics
The activities that take place in the Logo graphics environment are ideal for talking about the Logo aesthetics. However, the Logo aesthetics can transcend the graphics activities, although the aesthetics are much harder to implement in other educational software or even in other domains of Logo.
In other Logo domains, such as list processing, music, LEGO®Logo, and animation, the cycle of description-execution-reflection-debugging-description is certainly present, although each action in the cycle may not be as simple as in the graphics domain. The music domain, for example, has all the qualities of the graphics domain, although the description of sound ideas in terms of frequency is not that intuitive; and the reflection requires the ability to discriminate sound which can be a little harder than the discrimination of forms. List processing, on the other hand, is the domain in which the cycle is much harder to establish. First, the description of recursive processes is not very intuitive and it is not an everyday type of activity. Second, the execution of a recursive list-processing procedure is very opaque, making it impossible to see what the computer is doing. Third, the feedback provided by the computer is often insufficient to facilitate reflection. All of these factors make debugging a list-processing procedure very difficult. However, with a proper debugging facility, list processing can be less opaque, as was shown by Rocha (1993). Thus, it is not by chance that Logo is well known for its graphics!
Other computer software with menu-driven capabilities, such as Kid Pix or Paintbrush, makes the construction of beautiful objects very easy by just controlling the mouse. However, the fact that these software applications are not programmable or that they do not leave a trace when the activities are done, means that there is no description of the activity. Without the description, the description-execution-reflection-debugging-description cycle is truncated, and certainly debugging is undermined.
Software such as HyperCard® and Control Lab have programming capabilities in addition to powerful menu-driven facilities. However, the programming capabilities of these applications present problems. Either the type of programming they allow is simplistic to the point where it cannot be considered a window into the mind, or too intricate, providing a feedback that is hard to interpret, making the reflective and the debugging processes almost impossible. The problem with the programming capabilities in these applications stems from the fact that they were not implemented with the objective of facilitating the process of describing ideas. They are more concerned with achieving a product. In this sense the emphasis of the product design is on the computer, and the user has to mold his ideas to the computer. The design of a good learning tool needs to put the emphasis on the learner.
Even in the latest version of Logo, MicroWorlds®, we can get a lot done by just controlling the mouse. However, if we do not have a trace of these actions we have the same problems as we have with Kid Pix or Paintbrush. Also, if MicroWorlds adds much more, to a point that we have to ask "where's the program now?" (Adamson, 1993), certainly we are not moving in the right direction in terms of developing software to facilitate learning. In order to debug a program, we should be able to have the procedures, the values of the inputs that change the procedures' behaviors, and the results provided by these procedures all in one place so we can facilitate reflection and therefore debugging. If we have to look for the procedures attached to turtles, to buttons, to colors, and then look for sliders, we are distracting the user's attention from the debugging activity.
In order to be able to facilitate the construction of knowledge computer software needs to have certain aspects of the Logo aesthetics to easily engage the student in the description-execution-reflection-debugging-description cycle. The software should have a programming facility, or the computer should be able to collect information and construct a procedure as we select items from a menu, or do things on the screen. Some software developed within the visual programming paradigm has this feature. The trace becomes the description, as in "Mondrian," a program developed by Lieberman (1992).
Another reason that educational software should have these facilities is to be able to help teachers to be effective in the classroom computer environment. A teacher who interacts with many students at the same time is not able to dive into a learner's program and understand what is going on if the software does not contain a description of the student's work. If it is necessary to search for the program and/or if there is no trace of what has been done, it will take forever to understand the student's computer activity. Certainly this distances the teacher from the student's intellectual process and undermines the effectiveness of learning in the Logo environment.

In the early days of computers in education, Logo made a big impact because it provided powerful computational facilities for children and a completely different way of talking about education. Some of these facilities, such as graphics, were revolutionary considering the computer power available at that moment, and for many years Logo was the only educational software that allowed students to develop educational computer activities. The developers of Logo did everything possible and impossible to implement these facilities because they stressed important pedagogical issues. Even today the pedagogical innovations introduced by Logo, the Logo aesthetics, are an important landmark in education. People who still use and value Logo today do it because of its aesthetics and because of its potential as a revolutionary educational tool.
As the computer becomes more widely available in education it is clear that today we have many more software applications to choose from, each one requiring more or less effort to develop a final product. We no longer need to "program" the computer to draw a little house or to draw a sophisticated landscape scene. And that is fine if the objective is to get the product done. However, if we want to emphasize the use of the computer to enhance learning, we should not lose the Logo perspective. The criteria should be whether the software allows the student to engage in the description-execution-reflection-debugging-description cycle, and how effective each of the activities in the cycle is for the learning process.
In terms of the development of new versions of Logo, a special effort should be made to keep the Logo aesthetics clear and crisp. However, we should think about new ways of describing ideas to the computer. It does not need to be through a sequence of typed commands. The new features added should be analyzed in terms of the gains acquired in the process of facilitating learning and penetrating into the user's mind. This means that the development of Logo should be more an exercise about learning than the implementation of a diversity of new computational features.

Adamson, E. "Where's the PROGRAM?" Logo Update, (2) 1, Fall 1993

Clements, D H. and Meredith, J.S. "Is Programming Obsolete?" Logo Exchange, (12) 1, Fall 1993.

Lieberman, H. "Mondrian: A Teachable Graphical Editor" In Allen Cypher (ed) Watch What I Do: Programming by Demonstration MIT Press, Cambridge, MA, 1992

Papert, Seymour Mindstorms: Children, Computers and Powerful Ideas Basic Books, New York, 1980

Papert, Seymour "Is Programming a Good Activity for Children?" Logo Update, (2) 1, Fall 1993

Rocha, H.V. "Computational Representations as a Tool for Learning Symbolic Logo" Proceedings of the III EuroLogo, Athens, 1993

Solomon, C. "Introducing Logo to Children: Teaching Logo Requires an Awareness of Different Learning Styles" Byte (7) 8, 1992, pp. 196-208

Valente, J.A. "Computers in Education: Shifting the Pedagogical Paradigm from Instructionism to Constructionism". Logo Exchange, (12) 2, 1994, pp. 39-42.

Weir, S. Cultivating Minds: A Logo Casebook, Harper & Row, New York, 1987

José Valente may be contacted at:
Núcleo de Informática Aplicada Educagco
Universidade Estadual de Campinas
Cidade Universitaria
Pridio V da Reitoria - 2 Piso
13083-970 Campinas
SP - Brazil
Tel: ++55 (192) 39 7350
Fax: ++55 (192) 39 4717


The Turtle Is Dead
Rethinking Logo in the Age of Kid Pix

by Michael Tempel

At a recent Logo workshop a teacher asked me, "Why do we need Logo if we have Kid Pix?". I replied that Kid Pix can be used to produce a drawing, but with Logo you also learn geometry and planning and debugging skills while creating your picture. She seemed satisfied with my response, but I really wasn't. Maybe I had given her a good teacher answer, but is wasn't a good kid answer.
Here's an example of a turtle graphics project done 18 years ago in the Brookline Logo Project, a research project conducted by the MIT Logo group and the Brookline, Massachusetts Public Schools (Watt, 1979). Deborah drew a rabbit with pencil and paper and wanted to duplicate the drawing using Logo.

Her teacher suggested a modification of the drawing that would make it easier to reproduce on the computer.

After two weeks of work, Deborah succeeded in creating her rabbit using the Logo turtle.

In 1975, Logo was the best software tool available to draw that rabbit. But today, you could do it in a minute using Kid Pix, or use a scanner (which is what I did to get the images into this article). But Kid Pix and scanners don't teach geometry! Hold on. Let's get back to basics for a moment.
In Mindstorms, written in 1980, Seymour Papert tells us about the criteria that were used to design a "new mathematics" for children. What he said is worth quoting at length:

Turtle geometry started with the goal of fitting children. Its primary design criterion was to be appropriable. Of course it had to have serious mathematical content, but we shall see that appropriability and serious mathematical content are not at all incompatible. On the contrary: We shall end up understanding that some of the most personal knowledge is also the most profoundly mathematical. In many ways mathematics — for example the mathematics of space and movement and repetitive patterns of action — is what comes naturally to most children. It is into this mathematics that we sink the tap-root of Turtle geometry. As my colleagues and I have worked through these ideas, a number of principles have given more structure to the concept of an appropriable mathematics. First, there was the continuity principle: The mathematics must be continuous with well established personal knowledge from which it can inherit a sense of warmth and value as well as "cognitive" competence. Then there was the power principle: It must empower the learner to perform personally meaningful projects that could not be done without it. Finally there was the principle of cultural resonance: The topic must make sense in terms of a larger social context. I have spoken of Turtle geometry making sense to children. But it will not truly make sense to children unless it is accepted by adults too. A dignified mathematics for children cannot be something we permit ourselves to inflict on children, like unpleasant medicine, although we see no reason to take it ourselves.

Let's look at the rabbit project in light of Papert's three principles of an appropriable mathematics for children. Children move around in pretty much the same way as they did 18 years ago. The mathematics of the Turtle is still firmly rooted in the personal and natural "mathematics of space and movement" But using Logo in this way certainly does not empower today's child to do something "that could not be done without it," nor does the activity resonate with the way in which the adult world does computer graphics. The rabbit wins on continuity but loses on power and cultural resonance. One out of three ain't good.
Is this the end? Is the Turtle dead?

Not exactly. The turtle is a very adaptable creature and can do more than draw. In 1980 when Logo emerged from the Logo Lab at MIT and went into the real world of schools it came in two varieties. One ran on the Apple II. With a single triangular Turtle, its graphics capability was similar to that of the large research machine that Deborah used for her rabbit project. The other ran on a Texas Instruments TI99/4. This one was a flamboyant Logo with 32 brightly colored "sprites" that could fly around the screen and change shape to be birds, flowers, or space ships. In the early 1980s different branches of the Logo culture emerged, one around Turtle graphics and another involved with animation and video games. These two traditions have endured to this day.
The domain of animation and game programming measures up quite well against Papert's criteria for an appropriable mathematics. Getting a bird to take off, drop an egg on someone's head, and then return to the nest, or causing two spaceships to dock, or designing and building a pinball game are as much connected with the "mathematics of space and movement" as are drawing a house or a rabbit. They involve the same learnings about distance and direction, and also about time and motion.
Logo empowers the learner to create these action projects. Action-oriented programming resonates well with the modern culture in which computer games are commonplace, and computer-generated animation is part of movies, TV commercials, and the nightly weather report.
So where does that leave Deborah's rabbit? Now that we have Kid Pix, or for that matter MicroWorlds with its built in drawing tools, why do we need to draw with Logo? Is this the end for Turtle graphics?
Maybe not. Can you do this with Kid Pix?

to spiral :step :turn
if :step > 100 [stop]
forward :step
right :turn
spiral :step + 1 :turn

spiral 1 90

spiral 1 91

Long live the Turtle!

Watt, Daniel Final Report of the Brookline Logo Project Part III: Profiles of Individual Student's Work, Logo Memo No. 54, MIT. 1979, pp 4.10 - 4.17

Papert, Seymour, Mindstorms, Basic Books, New York, 1980, pp 53-54

Michael Tempel may be
contacted at:
Logo Foundation
250 West 85th Street, Suite 4D
New York, NY 10024
tel: 212 579 8028
fax: 212 579 8013


The Case for Classic Logo

by David L. McClees and Dorothy M. Fitch

Logo is a classic — timeless and enduring. Just as Treasure Island should be on every student's reading list, so should Logo be a part of every computer room's curriculum. Why? Because Logo's learning environment is the best one for teaching the lessons students need to learn.
Logo is a learning tool, an environment that helps you, the teacher, guide students to lessons that are important for their growth and education. As a teacher, you choose the best tool or tools to help you teach students what they need to learn. But how do you match the educational tool to what you want to teach?
To teach mathematics and programming, Logo is the best tool available. To teach problem-solving, it is one of the best available. Specifically, Logo was designed to be a world for exploring fundamental math concepts, for teaching programming, and for teaching powerful analytical concepts, such as sequencing, iteration, and structure (breaking large problems into smaller ones). If you can think in these terms, you can also analyze the world around you.
In particular, with computers becoming a part of all jobs in all workplaces, students will need to know how to use simple programming concepts, regardless of the language. Spreadsheet macro users are programmers. VCR owners (at least those who can set their machine to record future broadcasts) are programmers.
We believe that classic Logo is the best tool for learning these valuable concepts. What do we mean by "classic" Logo? We mean a traditional Logo:

What difference does it make which Logo you choose? Again, it depends on your learning or teaching goals. If you are graphing results of probability trials, it does not matter if the turtle looks like a triangle or a tyrannosaurus. If you are using Logo as a geometry construction tool, you probably won't need sliders and other gizmos. If you are simulating ant behavior, you might like to have multiple turtles with ant shapes over an "active" background. And if you are simulating a traffic scene, vehicle-shaped turtles that can move independently and perpetually may be useful.
By analogy, while an accomplished woodworker may wield a power router with ease, an apprentice woodworker can learn about wood's grain and textures by cutting, planing, and hand-sanding. Different environments and different tools encourage different thoughts and learning.
We have found that people like classic Logo because it continues to provide an environment in which (1) the focus remains on mathematics, programming, and analytical thinking, and (2) these concepts are easily taught.
Certainly some teachers always want the newest and latest. We do agree that modern interfaces offering more convenient "housekeeping," such as saving and printing, add to Logo without detracting from its core. However, many teachers believe that "bells and whistles" distract from the lessons they are trying to teach. They are concerned that as more and more conveniences are provided, students learn less and less about the underlying process. Some teachers prefer not to have an arc or circle primitive so that they can guide their students to a deeper understanding of a circle. Many teachers do not want students to be able to position the turtle with a function key. Rather, they believe students need to learn the math concepts involved, to experiment in order to fully internalize the lesson. To them, this is important learning; what makes Logo, Logo.
This is not to say that one can't learn math and programming using the newest versions of Logo. But how long will it take students to grasp the same concepts that are more readily attainable in classic Logo? In the limited time available, will students absorb the important learning Logo has to offer?
Recently, a high school teacher noted that she "gave the kids a 'real' Logo assignment (no paintbrushes and melodies and so on)." She reported that three out of fourteen kids asked if it were all right for them to use their 'old' Logo disks instead, "even though they could have done the same program in MicroWorlds® and just ignored the fancy stuff."
Even with "classic" Logo for the Macintosh, some teachers long for the simplicity of the unadorned Apple II Logo language. They prefer to focus on the lessons they wish to teach with Logo, rather than the "fancy stuff" that is possible.
Is there a place for classic Logo today? You bet. It offers the clearest and most powerful representation of what drew us all to Logo in the first place.

David McClees and Dorothy Fitch may be contacted at:
Terrapin Software
400 Riverside Street
Portland, ME 04103
tel: 207 878 8200
fax: 207 797 923
e-mail: 71760.366@compuserve.com