What is Logo?

"Logo is the name for a philosophy of education and a continually evolving family of programming languages that aid in its realization."

- Harold Abelson
  Apple Logo, 1982

This statement sums up two fundamental aspects of Logo and puts them in the proper order. The Logo programming environments that have been developed over the past 28 years are rooted in constructivist educational philosophy, and are designed to support constructive learning.

Constructivism views knowledge as being created by learners in their own minds through interaction with other people and the world around them. This theory is most closely associated with Jean Piaget, the Swiss psychologist, who spent decades studying and documenting the learning processes of young children. 

• In the Beginning

In the mid 1960s Seymour Papert, a mathematician who had been working with Piaget in Geneva, came to the United States where he co-founded the MIT Artificial Intelligence Laboratory with Marvin Minsky. Papert worked with the team from Bolt, Beranek and Newman, led by Wallace Feurzeig, that created the first version of Logo in 1967.

Throughout the 1970s Logo was incubating at MIT and a few other research sites: Edinburgh, Scotland and Tasmania, Australia. There were small research activities conducted in local schools, including the Brookline Public Schools, just up the Charles River from MIT. Dan Watt, Cynthia Solomon, and other MIT researchers documented their work with a small number of elementary school students using Logo. Their reports are among the several dozen Logo Memos published by MIT during this period.

The Logo Programming Language, a dialect of Lisp, was designed as a tool for learning. Its features - modularity, extensibility, interactivity, and flexibility -follow from this goal.

For most people, learning Logo is not an end in itself, and programming is always about something. Logo programming activities are in mathematics, language, music, robotics, telecommunications, and science. It is used to develop simulations, and to create multimedia presentations. Logo is designed to have a "low threshold and no ceiling": It is accessible to novices, including young children, and also supports complex explorations and sophisticated projects by experienced users.

The most popular Logo environments have involved the Turtle, originally a robotic creature that sat on the floor and could be directed to move around by typing commands at the computer. Soon the Turtle migrated to the computer graphics screen where it is used to draw shapes, designs, and pictures.

Some turtle species can change shape to be birds, cars, planes, or whatever the designer chooses to make them. In Logo environments with many such turtles, or "sprites" as they are sometimes called, elaborate animations and games are created. 

• Out Into the World

Widespread use of Logo began with the advent of personal computers during the late 1970s. The MIT Logo Group developed versions of Logo for two machines: The Apple II and the Texas Instruments TI 99/4. The Logo language itself was similar in both versions, but the video game hardware of the TI 99/4 lent itself to action-oriented projects, while the Apple version was best suited to turtle graphics, and language projects.

In 1980 a pilot project sponsored by MIT and Texas Instruments was begun at the Lamplighter School in Dallas, Texas with 50 computers and a student population of 450. At the same time the Computers in Schools Project was initiated by the New York Academy of Sciences and Community School Districts 2, 3 and 9 in New York City, and supported by Texas Instruments and MIT. Twelve TI 99/4 computers were placed in six New York City Public Schools. These were later joined by a few Apple IIs.

Both projects offered teachers extensive training and support through intensive two-week Summer Institutes and follow-up workshops during the school year.

These projects have had lasting results. Theresa Overall, who was a leader in both the Dallas and New York workshops, continued to teach Logo at Lamplighter and to offer summer workshops. Michael Tempel, then of the New York Academy of Sciences is now President of the Logo Foundation, a nonprofit organization that provides Logo professional development and support services to schools and districts throughout the world, including New York City Community School District 3. Two of the teachers who represented that district in the original project, Peter Rentof and Steve Siegelbaum, went on to form the Computer School, one of the District's alternative middle schools where Logo is still in use today.

The prototype Logo implementations used in those pioneering projects evolved into commercial products. TILOGO was released by Texas Instruments. Terrapin Software , a company that was set up in 1977 to distribute robot floor Turtles, licensed the Apple II version of MIT Logo and has marketed it and upgraded it to this day.

A new company, Logo Computer Systems, Inc. (LCSI) was formed in 1980. Many of the researchers, teachers, programmers, and writers who were involved in this venture have played major roles in the subsequent development of Logo. Seymour Papert is LCSI's chairman. Brian Silverman was Director of Research and guided the development of all of LCSI's products. Cynthia Solomon, who was on the team that created the original Logo in 1967, headed up LCSI's first development office in Boston and later directed the Atari Cambridge Research Center. Michael Tempel provided educational support services from LCSI's New York City office for ten years until he started the Logo Foundation in 1991.

LCSI developed Apple Logo, followed by versions for a host of other computers. With commercial availability, Logo use spread quickly.

Another important event occurred in 1980 - the publication of Seymour Papert's Mindstorms . Teachers throughout the world became excited by the intellectual and creative potential of Logo. Their enthusiasm fueled the Logo boom of the early 1980s.

New versions of Logo were implemented in more than a dozen spoken languages on a variety of machines, many with video game style graphics and sound capabilities. Logo for MSX computers was popular in Europe, South America, and Japan. Atari Logo and Commodore Logo were popular in North America.

Logo received considerable support from mainstream computer manufacturers. Apple Computer marketed LCSI's Apple Logo and, at one point, bundled it with the computers given away to each school in California. IBM marketed LCSI's IBM Logo and Logo Learner.

Atari not only distributed Atari Logo, but set up the ambitious Atari Cambridge Research Center under the direction of Cynthia Solomon .

By the mid 1980's the computers with video game capabilities had dropped off the market and taken their versions of Logo with them. MSDOS machines increasingly dominated the world of educational computing, except in the United States where Apple was the school favorite. Logo developers concentrated on these machines. Although new implementations added features and took advantage of the increased speed and memory of newer computers, the most popular versions of Logo in use in 1985 were similar to those of 1980.

Around this time there was also some interest in using Logo as a "serious" programming language, especially for the new Macintosh computer. MacLogo from LCSI added new functionality to the Logo environment. Coral Software, developed an object-oriented version of Logo called Object Logo. It included a compiler which allowed programs to run at higher speed, and stand-alone applications could be created. But Logo did not become popular among applications programmers. 

• Innovation

In 1985 Logo Computer Systems, Inc. introduced LogoWriter, which was novel in several ways. First, it included word processing capability - hence the name. Second, the user interface was simplified and made more intuitive. LogoWriter also included, as the earlier "sprite" Logos had, multiple turtles that could take on different shapes, although in this area the Apple and IBM computers on which LogoWriter ran were no match for the earlier game machines. LogoWriter was implemented in many spoken languages and became popular throughout the world.

Another innovation of the mid-eighties was LEGO Logo. Mitchel Resnick and Steve Ocko, working at the MIT Media Lab, developed a system which interfaced Logo with motors, lights and sensors that were incorporated into machines built out of LEGO bricks and other elements. Robotics systems with Logo were not new, but the popular and well-supported LEGO TC Logo was a commercial success which reached thousands of teachers and their students.

It was around this time that a unique series of Logo conferences took place at MIT. Beginning with LOGO '84 and continuing for two more years with LOGO '85 and LOGO '86, these meetings brought a worldwide community together at Logo's unofficial home.

In 1988 the Programa Informática Educativa was initiated in Costa Rica by the Omar Dengo Foundation, the Ministry of Public Education, and IBM Latin America. This  project put Logo in the hands of most of Costa Rica's elementary school students and their teachers. A similar project was initiated in Costa Rica's secondary schools.

The Costa Rican projects have provided extensive teacher education and support with a strong emphasis on Logo's contructionist educational approach. They have been taken as models for similar endeavors in a dozen other Latin American countries. Through the 1990s Latin American Logo enthusiasts came together every two years in a different country for the Congreso Logo.

In Japan, Logo saw growing acceptance in the country's schools where the original LogoWriter, then the enhanced LogoWriter2, and then LogoWriter Win were the most popular versions.

In England, Logo was a mandated part of the national curriculum. This guaranteed that Logo was widely, if not necessarily well used. England is also the birthplace of the extinct Valiant Turtle and the still extant Roamer.

There are Logo hot spots throughout Europe where there is a biennial EuroLogo conference.  Now renamed, this conference will next be held in Athens, Greece as Constructionism 2012. European Logo software developments have included WinLogo in Spain and Comenius Logo from Slovakia. 

• New Developments during the 1990s

A new version of Logo called MicroWorlds was released in 1993 by LCSI. It embodied major changes both in the Logo environment and the Logo language. It included many extra-Logo features - drawing tools, a shape editor, a melody maker, the ability to import graphics and sounds - that work along with Logo to support the creation of multimedia projects, games, and simulations. Microworlds has been upgraded several times and is available today as MicroWorlds EX.

MicroWorlds Logo includes a number of changes, the most significant being multi-tasking, or parallel processing. Several processes can be launched independently. This is invaluable when creating animations with more than one actor - the car can drive off a cliff while the dog wags its tail while the fat lady sings. This sort of thing is possible in a non-parallel Logo environment but it is far easier and more natural in MicroWorlds.

Control Lab and Control System were LEGO Logo products whose multi-tasking software was built on the same core as MicroWorlds.

Another LEGO Logo innovation was the Programmable Brick , a research project at MIT spearheaded by Fred Martin . Unlike earlier LEGO Logo products where the robot received instructions through wires connected to a computer, the Programmable Brick had a computer inside. A program written on a desktop or laptop computer could be downloaded to the Brick, which could then be detached from the host computer and run its program autonomously.

LEGO commercialized the programmable brick as the RCX and later the NXT in products called LEGO Mindstorms. Smaller versions of the Programmable Brick, called crickets, where also developed commercially as the Handy Cricket and PICO Cricket .

As part of the Programmable Brick project at the MIT Media Lab a new version of Logo called Logo Blocks was created.  Instead of writing lines of code in text, programs were built by snapping together jigsaw-like puzzle pieces.

A radically different Logo called StarLogo was introduced in 1994. It is a massively parallel version that was developed by Mitchel Resnick at MIT. Thousands of turtles can carry on independent processes and interact with each other and with patches of background. The system is specifically designed to facilitate the exploration of decentralized systems, emergent phenomena, and self organizing behavior. Resnick'sTurtles, Termites, and Traffic Jams is the source book on StarLogo and the ideas underlying its development.

A similar program called NetLogo was developed by Uri Wilensky, who now heads the Center for Connected Learning at Northwestern University. 

• The 21^st Century

In 2004 a new Logo programming enviroment called Scratch emerged from the Lifelong Kindergarten Group at the MIT Media Lab.  It uses the blocks programming paradigm that was originally implemented as Logo Blocks.  Scratch is well suited to desinging and building interactive stories, animations, games, music, and art. It can gather information from the outside world via a sensor board connected to the computer. The Scratch Web site provides the focal point for a community of over a million users who have shared more than two million projects.

Following from the popularilty of Scratch, blocks programming has become widespread and is used in a number of other Logo applications including Turtle Art, Scratch for Arduino, Build Your Own Blocks, and StarLogo TNG .

Meanwhile, traditional versions of Logo continue to be used.Brian Harvey, author of the three-volume classic Computer Science Logo Style wrote UCBLogo, a public domain version for Macintosh, MSDOS, and Unix.George Mills used the core of UCBLogo as the basis for his MSWLogo which runs under Windows with many enhancements that are possible in that operating system. FMSLogo is a more recent version based on MSWLogo.

After more than four decades of growth, Logo has undergone dramatic changes in step with the rapid pace of development in computer technology. The family of Logo environments is more divers than ever before.

Pavel Boytchev, who created Elica, has compiled the  Logo Tree , which lists all the versions of Logo, past and current, that he has information about. There are more than 250 of them.

Logo is a growing family of programming languages and a learning environments, and a worldwide community of people drawn together by a shared commitment to a constructivist educational philosophy.

To find out more about Logo you can continue to wander around this web site and check out the links to other sites.