Grassroots Invention Group. MIT Media ... expressive, and affordable interactive animatronic character .... ALF, there is great potential for direct interaction which.
ALF: Kids Making Faces Christopher Lyon and Bakhtiar Mikhak Grassroots Invention Group MIT Media Lab 20 Ames Street Cambridge, MA 02139, USA {scooby, mikhak}@media.mit.edu ABSTRACT
ALF, the Acrylic Life Form, is a programmable, expressive, and affordable interactive animatronic character built with less than a hundred parts that can be easily assembled by a young child and his/her parent in a single afternoon. ALF's modular design at both the physical and computational level provides children an engaging pathway to learn about fundamental preprogramming ideas and to develop their spatial reasoning abilities by constructing a friendly character whose facial expressions they can fully control. Due to ALF's modularity, children can design their own functional features to personalize ALF's design. We also present a tangible interface for direct interaction with and scripting behaviors for ALF. Finally, we discuss how ALF and its interface are an example of a non-trivial interactive system built with our own modular hardware and software toolkit. This toolkit is designed to make the integration of embedded electronics with handheld computers, desktop computers and intricate mechanical embodiments relatively easy. Keywords
Interaction design, design and prototyping toolkits, enduser programming, children, entertainment, education. INTRODUCTION
Arguably one of the most important inventions of the twentieth century, Kindergarten serves as an exemplary instantiation of the Constructionist approach to education. Kindergarten is a rare stage in formal education in which central prominence is given to the role of learning through interactions with carefully selected physical objects. The limited extension of the kindergarten approach to higher levels is, in part, a reflection of the lack of availability of learning tools appropriate to these upper levels, but not necessarily due to the lack of saliency of the core kindergarten ideas. This contention has been a central premise to some of the most inspiring work [6,11] done at the intersection of digital technology and learning tool design.
Figure 1: ALF- The Acrylic Life Form There are many points of view in the educational research community as to how to best take advantage of digital technologies in designing learning material and activities for children. In this regard, the Constructionist perspective differentiates itself from other approaches in that it not only provides a framework for the creation of tools that allow children to make things that they deeply care about, but also provide a research methodology for studying what children learn in the process of making things with these tools.[6,9] Ubiquity of more and more powerful digital technologies provide a wide range of opportunities for the development of rich, playful learning activities and interactions. -1-
Furthermore, there is a unique opportunity to provide educators with the means to become the creators of the learning materials and experiences that they find most appropriate to empower their students with learning tools.
FaceMaker that can be easily extended to include programming interfaces with direct feedback and control. INTERACTION SCENARIOS
In the context of a classroom setting, there are a wide variety of possible interactions that students can have with ALF. Potential scenarios for the use of ALF arise from differing student/ALF ratios, ranging from close, individual learning experiences, to extensively collaborative group activities. While the ways in which ALF is used vary significantly, regardless of the ratio, there is still a substantial basis for a stimulating activity. In Table 1, we have illustrated a rough guideline for how we feel that ALF can best be used given the environment.
In this paper, we present ALF, a system that exemplifies the constructionist design principles in so far as it not only provides educators with a tool for introducing children to important preprogramming ideas through an expressive activity, but also the tools to extend our system to develop new materials that provide multiple entry points and support different learning styles for introducing children to many important ideas. MOTIVATION
The next phase of the digital revolution is to go beyond personal computation to personal fabrication. [8] This prediction will have a far-reaching impact and in order to recognize its full implications, we must think of fabrication in broadest terms. For example, people today enjoy a much greater degree of control over the creation, manipulation, and processing of their still pictures and videos. And soon there will be a wide collection of affordable tools that will allow one to make their own physical artifacts, and for our children to get the most benefit from these capabilities, they need to learn not only to design and manipulate their creations on computers, but also to use computer controlled manufacturing tools to build and realize their creations. We believe that an important part of this preparation is learning how to program and for this and many other similar reasons programming, in one form or another, will become a very important basic skill. Undoubtedly, what we will mean by programming will come to take many forms, as the incentives and paradigms for programming change to meet the demands of growing diversity in applications. What will not change in nature is the need to introduce to children the important ideas in computation through innovative creative and playful activities [3]
Table 1: The Many Uses of ALF In a one-on-one activity between a single child and an ALF, there is great potential for direct interaction which provides a means for the child to truly explore ALF on his or her own terms, experimentally testing the limits of the system and shaping their play to the direction that most interests them. The first time a kid sits down to play with ALF, they usually start by just clicking the buttons corresponding to different features. As ALF immediately responds by moving accordingly, they are met with instant gratification and beginning clicking lots more buttons to test out all his different movements. From there, a kid may wants to start making faces. They tell ALF to make silly faces- eyebrows up, mouth wide-open, head turned to the side, and then contort their own faces into similar patterns, mimicking what they see before them. But then they start asking about those other buttons on the interface, and what that empty box is for. As soon as you show them how simple it is to click the motion buttons in order and make ALF play back that sequence of commands, they generally grab the mouse away from you and start clicking every single motion, and watch ALF do exactly what they told him to, in order.
The central premise of much of the most innovative work in
research the area of technologies for learning is that the most salient pre/programming ideas, given the right tools and materials to interact with, are very natural for children to grasp and put to use effectively.[10,12,14] Furthermore, there is research that show that many of these ideas can be even made accessible to even younger children (as young as 4.5).[13, 16] A few examples of such pre/programming ideas are sequential thinking, cause-and-effect relationships, and encapsulation. Developing programming environments for novice users is an active area of research [1], which was a direct inspiration for ALF. Another source of inspiration for ALF were classic programming environments for kids from the early days of personal computers. In this regard, one notable example is the FaceMaker1 software. ALF is a physical counterpart of 1
Once a kid has successfully mastered programming an ALF, a new challenge is introduced- a second ALF! Now the goal is to make them talk to each other. This introduces critical new thinking skills to the students. It’s no longer as simple as programming two ALFs. They can’t just look
A product made in the early 1980’s but not available today. -2-
Any tool that can completely capture the imagination and sustained attention of a child this young is an excellent entry-point for teaching a wide variety of concepts, and can be easily adapted to fit many possible situations.
like they’re talking to each other; they actually have to communicate, taking turns in a conversation just like people would. A scenario like this further explores the applications of cause-and-effect relationships, as a child now snaps on the infrared(IR) communication layer, and discovers a new button in the interface that sends an “I’m Done Talking” command to the other ALF. As a new ALF is connected, a second tab appears in the interface, with a small picture of the new ALF. Each ALF has their own set of buttons and program window, and both programs can be written simultaneously. At first, the child might struggle with the interaction- ALFs getting confused and interrupting each other, losing synchronization, and otherwise not working as desired. Multi-system interaction is not a difficult concept to grasp, especially for someone this young and inexperienced, but with a tool like ALF, the child is capable of grasping these challenging concepts in a comparatively short amount of time. With an hour or two, they child is demanding more ALFs! She wants to put on a show and make them all sing together, and “dance.”
As more children are introduced, playing with ALF becomes a collaborative learning experience, in which the children must work together to explore EDUCATIONAL IMPLICATIONS In this section, based on a framework used for discussing the educational implications of a class of toys called Curlybot, [4] we will discuss the complementary educational opportunities afforded by ALF in light of its potential to: • serve as objects-to-think-with [10] • make new domains of knowledge accessible or old domains of knowledge approachable in new ways • support multiple learning styles [17] ALF as an object-to-think-with
Because of the anthropomorphic characteristics of ALF, it is common for children to want ALF to imitate them. In a typical interaction, children begin by exploring ALF to figure out which of his features can be animated. They then, after deciding what they wan ALF to do, proceed to very naturally articulate how they would break those actions down into a sequence of steps through which the various features of ALF need to go. Furthermore, they can immediately execute every step, one at a time, on the physical ALF and see if it did what they expected. This quality of ALF is not unlike the important body-syntonic qualities of the LOGO programming language that Seymour Papert wrote about more than two decade ago, as well as the Curlybot toys that was deeply inspired bythe ideas underlying LOGO. In Mindstorms, Papert eloquently describes the significance of programming as a tool for thinking about one's own thinking [10]. The very process of externalizing models and concepts in ones mind into the physical world allows for the critical evaluation of the validity of the models by oneself and others against easily understandable physical behavior. In turn, the external instantiation of an idea can be internalized again to modify the initial models. ALF, much like Curlybot, takes advantage of the rich educational opportunities afforded by creating and supporting such internalization/externalization feedback loops.
But what about when there is more than one kid playing with ALF or a group of ALFs? In some cases, a much richer interaction is now possible, because in addition to learning about what ALF can do, kids have to work together in an extremely powerful collaborative learning environment. While there is much to be learned about teamwork from agreeing on how to make ALF move and what to make him say, in many ways there is even more to be learned from disagreement. Imagine two kids with two ALFs trying to carry out a dialog. Each kid wants to do his or her own thing. They can’t seem to agree, and each goes and writes their own side of the dialog. When they try to run it, near chaos ensues, ALF’s talking over each other, and the kids blaming each other for it not working. However, as they work through this collaborative disagreement, they gain not only valuable interpersonal experience, but work through the difficult problem of interobject communication together, helping each other overcome confusing obstacles as they arrive at them. Another valuable way that individuals might interact with ALF is in a larger classroom setting. In a situation like this, a teacher could motivate a classroom brainstorming session around what ideas students have for things they could use ALF for. One girl wants to have ALF sing her favorite song. Another child suggest having ALF give the morning announcements to the class instead of their “boring” principal. Yet another wants ALF to do his homework. The students can then break up into smaller groups and start playing around with ALFs to help refine their ideas and develop new ones. After groups share their ideas with each other and constructive comments are made, the kids can break down into much smaller groups of one or two students per ALF, and really begin exploring and interacting with ALF in an environment similar to the ones previously described.
ALF and new domains of knowledge
One of the most common activities children envision with ALF involves two or more ALFs in a conversation with each other. Coordinating two more ALFs in a conversation, even if fully scripted and timed, allows children to thinks important ideas in human communication such as turn taking and a shared conceptual point of reference. [2] The full ALF system allows kids to examine and reflect on structural, functional, aesthetic qualities of ALF. At the structural level assembly an ALF, thanks to its modular mechanical structure, allows children to reflect not only on the elements in ALF’s design that contribute to its static
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and dynamic stability, but also components that have very specific functional and aesthetic roles.
assembled using acrylic cement, which is not only extremely toxic to use, but provides quite a bit of frustration as a small drop of glue tends to glue everything in the immediate vicinity into a single block of plastic. Sadly, a few ALFs were lost in this process, and have now been relegated to stationary shelf décor. At that point in the design cycle, ALF was entirely cut out of 1/8” acrylic, which made some of the 200+ pieces extremely delicate in the hands of a child. Many of the pieces were also quite small and unfortunately indistinguishable from scraps during the cutting process, leading to the unfortunate need for the re-cutting of pieces, an alternative that is obviously not viable in a classroom setting.
ALF and multiple styles of play and learning
An equally important component of any powerful learning experience is the affective quality of the relationship the learner develop with the things they are leaning with and about. Studies have shown that children's learning and play patterns can be divided into two overlapping categories, namely patterners and dramatists [15]. In the design of ALF, we were conscious of supporting both forms of play. For example, some children liked enjoyed the game of looking for specific ALF parts in a completed ALF while others were more interested in exploring ALF’s expressive possibilities. SYSTEM DESIGN
ALF himself is a tightly integrated example of a tool that can be used to teach principles of mechanical design, electronics, and software engineering. At its simplest level, ALF is a robotic head, with his electronics attached to the back of his head, and can be programmed by a direct connection to a desktop or handheld computer. A general system diagram is presented in Figure 2. Figure 3: Template for all of ALF’s pieces. In the most major design overhaul, ALF was completely reengineering using thicker ¼” acrylic, at the same time reducing the part count to around 75 actual pieces of plastic, and modifying all connections to allow a nut-andbolt assembly instead of gluing. Originally, ALF used eight tiny servo-motors that were quite expensive due to their miniature size. As part of the durability revisions, the motors were replaced with much stronger ones, but due to their larger size, were less than half the cost of the previous ones. At the same time, ALF was reduced to six degrees of motion, helping to further reduce cost and increase the durability of the system as a whole. What we arrived at was an extremely easy-to-assemble, durable, low-cost version of ALF, that can withstand even the most painful abuse. In fact, ALF has survived falls off of tables, and lived to tell about it. One neat feature of ALF, is the ease with which new facial features can be designed and used to change the way ALF looks, giving kids an important creative outlet and the means by which to personalize their ALF to their liking. Another key project in our group is the design and development of low cost fabrication equipment, and simple interfaces to it, to give everyone the ability to make new features for ALF, and eventually entire ALFs entirely on their own.
Figure 2: ALF functional diagram. Mechanical Design
In its physical form, ALF is a collection of less than a hundred total pieces of laser-cut acrylic, 6 servo-motors, and a handful of nuts and bolts. A great deal of effort has been put into the optimization of ALF’s mechanical design, to the extent where it is a durable, simple, assembly that can be done with minimal tools in a single afternoon.
Electronics Design
All along, a main goal of our design was to make ALF an easy-to-assemble set of pieces that could all be cut out of a single sheet of acrylic. Figure 3 shows all of ALF’s pieces on a single sheet. ALF has undergone significant revisions since its initial introduction. At first, ALF was entirely
At the core of ALF’s electronics subsystem, is the Tower[pending], a modular electronics design environment we have created to allow easy snap-together design of complex electronic systems. Shown in Figure 4, the Tower
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is comprised of a Foundation module with the core processor on it, and other boards that stack on top of it, providing a wide range of functionality including sensing, actuation, data storage, and communication.
already undergone several revisions as we have evaluated different approaches geared at simplifying and streamlining the programming process. An initial pass at the software is shown in Figure 5, and the more refined version currently in use can be seen in Figure 6.
Figure 5: PrototypeALF Interface Software
Figure 4: The Tower In its simplest form, all ALF really needs is the ability to drive servo-motors. To accomplish that with the Tower system, you just need the Foundation and a Servo layer. It’s as simple as connecting the two modules together, and plugging in a serial cable to begin programming it from a computer or handheld device. However, most of the options for rich interaction between students and ALF require more powerful electronics support. Children can pick and choose from a wide variety of modules in the system, and can give ALF the ability to know when people are near it, speak, sing, and even to learn, remembering details from its previous interactions with individuals.
Figure 6: Current ALF Interface Software
With the presence of such an open toolkit on the electronics level, we have provided a pathway for kids to really get involved in the low-level system design and further expand and develop ALFs abilities and behaviors.
With both sides of the software written in LOGO, the algorithms are extremely transparent to the extent where any user, regardless of their age or experience can get “under the hood” and tweak things to further personalize the system to their needs.
Software Design
ALF actually has two levels of software. First, there is user code written for the actual Tower in the LOGO language, which parses data coming from the user interface and causes ALF to respond accordingly. Secondly, there is the user-interface software, which has taken several different forms over the course of our work, ranging from completely graphical personal computer interfaces, to a tangible user interface, driven by a second tower sending commands to the first.
As kids plug a Sensor layer onto the Tower, they can easily add just a few lines to the Tower code to make ALF turn his head as a person walks by, or raise his eyebrows when he hears a sudden noise. At the same time, if they want direct access to those new Sensor values from the graphical interface, its again an easy task, simply requiring the addition of a display box and a short function that asks the Tower for the sensor reading. Interface Design
For initial interaction, most users begin with our graphical interface software. The portion of the software residing on the Tower is pre-programmed, and is essentially just a lookup table which translates serial commands to servomotor controls. The desktop computer side of the software is currently implemented as a project in the Microworlds[7]software, a graphical environment for LOGO programming. In fact, the graphical software has
Currently, we have two different interfaces to ALF, and a third is under construction. In operation now are the graphical interface mentioned above, and control box interface, which is essentially a physical version of the computer interface, complete with arcade-style buttons and lights. The control box is shown in Figure 7. We are actively working on a large-scale interface designed for a museum or other public installation. -5-
collaborating to create multi-ALF dialogs, songs, or any other types of interactions they can imagine. PRELIMINARY STUDIES AND RESULTS
So far, ALF has seen several forms of interaction with actual users. He has been presented to groups of visitors, and played with by some of them, used by exhibit designers who are familiar with creating interactive experiences, and become the focus of a directed workshop with a very eager four-and-a-half year old. The MIT Media Lab is visited by at least 5 of its 170+ sponsoring companies every day. Many of our visitors are from technical or research departments within their companies. In particular, many educators who work in both formal and informal educational environments at all levels frequently visit the learning research groups at the lab. During numerous visits, we had the opportunity to discuss ALF with professors from schools of education from many different countries, exhibit developers form various science and children’s’ museums around the world, and schoolteachers. We have received invaluable feedback from these groups, much of which has already been incorporated into the various redesigns of ALF. There has been a great amount of interest from representatives of all of the groups mentioned above to acquire copies of so that they can use it in their own contexts. Now that ALF is in a stable form, we are planning on working with them to make this possible and capture and communicate the lessons learned in a variety of contexts.
Figure 7: ALF Interface Box The graphical software has was designed with a very playful look and feel, and has a click-and-play interface inspired by the classic Facemaker software from the early 1980’s. The software has two modes, record and play. In play mode, ALF acts as just responsive output- opening his mouth when the “Mouth Open” icon is pressed, turning his head when the “Turn Head” icon is pressed, and responding to all other motion commands in a similar manner. Once kids are familiar with ALF and his motions, they have the opportunity to write simple programs for him. To write a program, its as simple as clicking the record icon, followed by any sequence of motion buttons. The sequence of motions will automatically be entered into the program window, and can be played back on ALF at any point in time.
By far one of the best experiences we’ve had with ALF, was the afternoon we spent introducing him to a young child named Ben. Even though he was only four and half years old, Ben was really excited about programming, and had even done a little before. We let him use both the physical interface, and the graphical one. Although he enjoyed pressing the buttons on the interface box, the graphical one seemed to attract his attention more, due to its vibrant colors and pictures of ALF’s facial features. We spent about an hour programming ALF to do different things, and used a Speech module for the Tower to give ALF a voice. However, most of his interest in programming went out the window when we showed him that ALF’s facial features could be removed and replaced with different ones. After swapping around features, he really wanted to make his own, so we let him use our design software to make a new part. He made a “hat”, and we eagerly ran downstairs to make it on the laser cutter. After cutting it and bringing it back upstairs, we put it on ALF and he was thrilled. After a little more programming, he discovered the box of parts for another ALF sitting on the floor under the desk. We invented a game, in which I would pull a part out of the box, and he would have to figure out where it actually goes in the assembled box. We went through every part in the box, some of them two or three times before he finally had to leave.
The physical interface box was created as an initial prototype for a museum interface, and is modeled almost directly after the software, with physical buttons replacing the icons, and a PalmPilot acting as the program window display. With lights and a toggle switch to select between Record and Play modes, this interface has proven to be a fun alternative to our initial one. We have begun work on an interface geared towards largescale installations, directly motivated by the use of ALF in an upcoming museum exhibit on robotic-human interaction being designed by the Science Museum of Minnesota. ALF is currently on display in their Playful Invention Center on the main exhibit floor. The new interface will be wall-sized, with huge facial features, and interaction with ALF is accomplished by moving the actual features on the wall. To record a simple sequence, a kid just has to hit the record button, and start moving on the features on the wall while it records. The whole thing can then be played back on ALF so the kids have direct feedback for their programming experience. We are also actively exploring the possibility of installing two ALFs and their interfaces as part of the exhibit, introducing the concept of communication between distance entities, and encouraging visitors to interact with each other as well as ALF,
An experience like this shows how many different levels ALF really works on. ALF gave Ben the opportunity to
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program, play around with motors and sensors, learn about mechanical functions, and even how to design things on the computer and actually make them.
2.Borovoy, R. (1996) Genuine Object Oriented Programming: A New Integration of Physical and Computational Media in a Children's Construction Environment. Masters Thesis.
VISION AND FUTURE STUDIES
As ALF is just beginning to enter his widest stage of fieldtesting in the context of the Museum exhibit, we are in the process of evaluating future research directions for the project. Since the overall system design is a product that we are happy with, our efforts are primarily focused on novel interfaces design, and designing activities to use ALF to his fullest potential in classroom and other settings.
3.Druin, A., Hendler J. (eds.) (2000). Robots for Kids. Morgan Kaufmann Publishers, San Fransisco, CA 4.Frei, P., Su, V., Mikhak, B., Ishii, H. (2000). curlybot: designing a new class of computational toys, Proceedings of the CHI 2000, p.129-136, April 01-06, 2000, The Hague, The Netherlands 5.Kafai Y., and Resnick, M., (eds.) (1996). Constructionism in Practice: Designing, Thinking, and Learning in a Digital World. Mahwah, NJ: Lawrence Erlbaum.
One of the primary difficulties we have observed as users interact with ALF, is the challenge they face when trying to synchronize ALF’s movements to speech or other timecritical cues. The current software is just a linear program mapping, so synchronization requires careful use of time delays to achieve the desired effect, which can be a very stressful process for inexperienced users. We are envisioning a software interface similar to what can now be found in animation and video-editing software, with a timeline-based approach to event sequencing, where independent events can be inserted on different tracks, and easily aligned as the user desires. With a separate track for each feature movement, and one for audio, as well as communication and sensor channels, kids would be able to easy program complex time-based animations which synchronize perfectly with recorded or synthesized voice. Additionally, complex patterns of motion can be further streamlined by the use of keyframing, a technique commonly used in animation which requires the user to only mark extreme points in the motion path, and then automatically interpolates the sequence, adding in the appropriate timing and motion controls for fluid animation.
6.Lifelong Kindergarten Group at the MIT Media Lab, and their projects and publications. 7.MicroWorldsTM Software Environment, 8.Mikhak, B. Project: The pleasure of making things. 9.Papert, S. (1991). Situating constructionism. In Papert & Harel, (eds.), Constructionism. Cambridge, MA: MIT Press and other papers therein. 10.Papert, S. (1980) Mindstorms: Children, Computer and Powerful Ideas. New York, NY: Basic Books, Inc. 11.Resnick, M. (1998). Technologies for Lifelong Kindergarten. Educational Technology Research and Development, vol. 46, no. 4. 12.Resnick, M. (1994). Turtles, Termites, and Traffic Jams. MIT Press.
Soon, we will run more workshops with small groups of kids, encouraging them to play out some of the scenarios we have envisioned. As these smaller workshops help to solidify a core set of activities centered around ALF, they will become a stepping off point for a full-scale deployment of ALF, making kits and the supporting tools available to educators and a wide variety of academic institutions.
13.Resnick, M., et al. (2000). Learning with Digital Manipulatives: New Frameworks to Help ElementarySchool Students Explore "Advanced" Mathematical and Scientific Concepts . Proposal to the National Science Foundation. 14.Resnick, M., and Ocko, S. (1991). LEGO/Logo: Learning Through and About Design. In Constructionism, edited by I. Harel & S. Papert. Norwood, NJ: Ablex Publishing
ACKNOWLEDGMENTS
15.Shotwell, J., Wolf. D., and Grdner, H. (1979). Exploring Early Symbolization. In B.Suttonm-Smith (eds.). Play and Learning.
We thank John DiFrancesco for assistance with the rapid prototyping machines, Brian Silverman for his continued contribution to the development of the tower system, and the members of the Grassroots Invention Group at the MIT Media Lab (http://gig.media.mit.edu/people).
16.Smith, C. (1999-2001) Collection of projects developed at the MIT Media Lab http://web.media.mit.edu/~csmith/tinkerers.html
REFERENCES
1.Begel., A. Logoblocks: A graphical programming language for interacting with the world. MIT Media Laboratory, 1996.
17.Turkle, S., & Papert, S. (1990). Epistemological Pluralism. Signs, vol. 16, no. 1.
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