Symbol Systems and Thinking Skills: Logo in Context
Roy D . Pea
C e n t e r for Children a n d Technology
Bank S t r e e t College of Educ a t 'ion
610 West 112th, New York, N Y 10025
Imagine y o u r s e l f a s a visitor t o a traditional farming society i n West
Africa.
You have a r r i v e d a s a cross-cultural psychologist to s t u d y
whether and how literacy affects t h e way people t h i n k .
Let u s begin b y
peering into y o u r mind to find o u t why you a r e h e r e .
The acquisition of literacy had long b e e n claimcd to promote t h e
development of intellectual skills.
Prominent h i s t o r i a n s and psychologists
had long a r g u e d t h a t written language h a s many important properties t h a t
distinguish i t from o r a l l a n g u a g e , and t h a t t h e u s e of written l a n g u a g e
leads to t h e development of highly g e n e r a l t h i n k i n g abilities, s u c h a s
logical reasoning a n d a b s t r a c t t h i n k i n g .
Piagetian s t u d i e s in o t h e r
c u l t u r e s had made clear t h a t t h e kind of a b s t r a c t thinking associated with
formal operations did not develop in oral c u l t u r e s .
By c o n t r a s t , when
o n e looked a t c u l t u r e s t h a t u s e d written l a n g u a g e , v a r i o u s cognitive t a s k s
revealed high logical competencies.
Rut you h a d o b s e r v e d t h a t s t u d i e s b e a r i n g on t h i s claim had always
been done i n societies s u c h a s Senegal o r Mexico, w h e r e literacy a n d
schooling were confounded.
P e r h a p s schooling i s responsible for t h e s e
c h a n g e s i n t h i n k i n g , r a t h e r t h a n t h e u s e of w r i t t e n language p e r se.
The reason you h a v e travelled to Africa i s t h a t you plan to t e s t , f o r
t h e f i r s t time, t h c cognitive e f f e c t s of literacy i n d e p e n d e n t l y of schooling.
T h e society you a r e s t u d y i n g - - t h e Vai--does not transmit literacy in t h e
Vai written language t h r o u g h formal schooling. T h e i r reading and writing
a r e practiced and learned t h r o u g h t h e activities of daily life.
The Vai i n v e n t e d t h e i r written language a mere 150 y e a r s b e f o r e ,
a n d have continued t o p a s s on literacy to t h e i r children without schools.
Like all t h e psychologists before y o u , you have b r o u g h t along
s u i t c a s e s filled with s t a n d a r d i z e d psychological t e s t i n g i n s t r u m e n t s a n d
stimuli for experiments on concept formation and v e r b a l reasoning.
Results from performances b y t h e Vai with and without written language
experience will tell you w h e t h e r possessing l i t e r a c y affects t h e way t h e s e
people t h i n k .
Rut a s you look o v e r y o u r r e s u l t s from s e v e r a l y e a r s of work, you
For
s e e no general cognitive e f f e c t s of being l i t e r a t e in t h e Vai s c r i p t .
example, t h e l i t e r a t e Vai were n o b e t t e r t h a n t h e nonliterate Vai in
categorization skills o r syllogistic r e a s o n i n g .
Literacy per s e does not
a p p e a r to produce t h e g e n e r a l cognitive effect- on h i g h e r thinking skills
you expected.
I!ow could this bc? T h e
So you mull o v e r t h i s fact for some time.
arguments were s o plausible for why written l a n g u a g e would affect t h e
way people think.
carefully?
You wonder--could
the s t u d i e s have been done more
But before continuing this research s t r a t e g y , you realize that t h e r e
is a radically d i f f e r e n t way to think about your project.
When you
a r r i v e d you took for g r a n t e d the g r a n d theory t h a t literacy will have i t s
general effects, and t h e n looked to s e e i f it did s o b y testing for general
intellectual benefits.
But with several y e a r s of s u r v e y and ethnographic
observations u n d e r y o u r b e l t , you have come to b e t t e r u n d e r s t a n d t h e
t a s k s t h a t Vai l i t e r a t e s encounter in their e v e r y d a y practices of literacy.
But how does t h i s r e l a t e to your experiments?
What you decide you could do instead is to actually look to see how
literacv is ~ r a c t i c e d in t h e Vai c u l t u r e .
What is done with the written
language? And then you ask a v e r y different t y p e of research question:
How could what t h e Vai people do specifically with t h e written language
affect their processes of t h o u g h t ? You decide to let your fieldwork on
literacy practices dictate t h e design of "outcome" t a s k s and you gain a
g r e a t deal of precision in your hypotheses for t h e cognitive effects of
literacy.
This reorientation literally t u r n s y o u r theory-driven paradigm of
looking for general cognitive effects of literacy on i t s head.
You have
shifted from making general predictions in terms of developmental t h e o r y
about concrete b e h a v i o r s , to s t a r t i n g with concrete observations of
literacy behavior a n d building up to a general functional theory of
literacy's effects.
With t h i s new approach you find t h a t t h e Vai u s e t h e i r written
language primarily for letter-writing, and for recording lists and making
technical farming plans.
Then you begin a new phase of your r e s e a r c h project, seeking out
cognitive e f f e c t s of specific literacy practices r a t h e r than literacy pel- s e .
You design new t a s k s for assessing literacy effects t h a t draw on related
skills to those r e q u i r e d b y t h e practices y o u o b s e r v e , b u t which involve
different materials.
What you find when directed b y this new functional perspective a r e
dramatic cognitive effects of literacy.
But t h e y a r e more local in n a t u r e .
For example, l e t t e r writing, a common Vai literacy practice, r e q u i r e s more
So
explicit rendering of meaning than that called for in face to face talk.
you refine a communication t a s k where t h e r u l e s of a novel board game
must be explained to someone unfamiliar with i t , e i t h e r face to face o r b y
dictating a letter for an a b s e n t person.
You f i n d , lo and behold, t h a t
performances of Vai literates a r e vastly s u p e r i o r on e i t h e r version of t h i s
t a s k to those of nonliterates.
This is no mere parable.
It is an account of an extensive five-year
r e s e a r c h project carried out by Professors Sylvia Scribner and Michael
It i s t h e account of an intellectual voyage not s o f a r
Cole ( 1 9 8 1 ) .
removed from what I h a v e to s a y about what children learn with Logo, f o r
we can fruitfully apply t h e schema of this Vai s t o r y to questions about
t h e cognitive effects o f programming.
Here, too, t h e r e a r e p e r s u a s i v e and intuitively appealing a r g u m e n t s
for why people should become b e t t e r t h i n k e r s b y v i r t u e of t h e use of a
powerful symbol system s u c h a s t h e Logo programming language.
It i s
alleged t h a t children will a c q u i r e general cognitive skills such a s planning
abilities, problem solving h e u r i s t i c s , and r e f l e c t i v e n e s s on the r e v i s i o n a r y
c h a r a c t e r of t h e problem solving p r o c e s s itself.
The f e a t u r e s o f
programming l i t e r a c y assumed h e r e include t h e necessarily explicit n a t u r e
of writing program i n s t r u c t i o n s , t h e s t r a t e g i c a n d planful a p p r o a c h e s
i n g r e d i e n t to modular program d e s i g n , a n d e x p e r i e n c e with t h e logic of
conditionals, flow of c o n t r o l , a n d with program d e b u g g i n g .
But for programming l a n g u a g e s , unlike written language, we do not
have t h e benefit of known historical and c u l t u r a l c h a n g e s that a p p e a r to
r e s u l t in p a r t from c e n t u r i e s of u s e of t h e written language.
The symbol
systems provided b y programming l a n g u a g e s a r e relatively new.
They
have certainly changed t h e world; we now live in a n information a g e
because of achievements made possible b y t h e s e languages.
But what
does i t mean for how individuals think and l e a r n ?
Let u s move o u r West African s t o r y to t h e context of t h e American
Classroom.
Here again we e n t e r a s p s y c h o l o g i s t s , looking for g e n e r a l
cognitive effects, much like t h e f i r s t literacy q u e s t i o n s of t h e African
enterprise.
Of c o u r s e we assume t h a t we know what kind of a mind-altering
s u b s t a n c e programming i s ( h a v i n g been s o affected o u r s e l v e s ) , a n d we
assume t h a t "programming intelligence" a n d t h e k i n d s of programming
activities c a r r i e d o u t b y a d u l t s will affect children too.
But we should g i v e pause--for we h a v e e n t e r e d a n o t h e r c u l t u r e .
What will children do with a programming l a n g u a g e in a discovery-learning
s i t u a t i o n , Logo's " l e a r n i n g without curriculum" p e d a g o g y , without benefit
of being shown what k i n d s of t h i n p s can be d o n e , o r being t a u g h t a b o u t
t h e powers of t h e system o r of thinking skills?
.
i'!onetheless.
without benefit of s u c h hirldsight,
what do o u r
psychologists in t h e Logo classroom do? They too look for programming's
" e f f e c t s , " guided b y somewhat t h e same kind of thinking that possessed
t h e f i r s t p h a s e of t h e Vai s t u d i e s .
T h e primary difference was t h a t
i n s t e a d of t e s t i n g for increments in g e n e r a l intelligence, o r concept
formation, they t h o u g h t t h e y were looking a t more specific e f f e c t s , q u i t e
plausibly linked t o programming activities.
Planning skills were t h e
central focus, not a b s t r a c t r e a s o n i n g , which i s only indirectly related t o
programming.
The psychologists' reasoning went something like t h i s : Rot11 rational
analyses of programming a n d observations of a d u l t programmers show t h a t
planning i s manifested in programming in important ways.
Once a
programming problem i s formulated, t h e programmer often maps o u t a
program plan o r design t h a t will then b e w r i t t e n in programming code.
E x p e r t programmers s p e n d a good deal of t h e i r time in planning program
d e s i g n , a n d have many planning s t r a t e g i e s available, s u c h a s problem
decomposition, modular documentation, subgoal g e n e r a t i o n , retrieval of
known solutions, a n d evaluative analysis
components ( c . g . Pea & K u r l a n d , 1 9 8 3 ) .
anti
debugging
of
program
Our psychologists s t ~ i d y i n g t h e cognitive effects of Logo c r e a t e d
planning t a s k s to r e v e a l t h e development of different planning s t r a t e g i e s ,
a n d of skills a t plan revisions analogous to program revisions. In two
d i f f e r e n t s t u d i e s , a f t e r a y e a r of Logo programming, t h e s e psychologists
f o u n d no effects of programming on performances i n t h e s e planning t a s k s
Children improved with a g e a n d practice on t h e
(Pea & R u r l a n d , 1 9 8 4 ) .
planning t a s k s , b u t non-programmers did just a s well a f t e r a y e a r ' s time
a s did Logo programmers.
Once a g a i n , like t h e r e s e a r c h e r s in West
Africa, we must reflect on o u r f i r s t s e t of assumptions for framing t h e
r e s e a r c h q u e s t i o n s , and r e c o n s i d e r t h e meaning o f o u r r e s e a r c h findings.
Let u s t a k e a d i f f e r e n t , functional o r activity-based approach t o
programming. Consider "programming" not a s a g i v e n , whose f e a t u r e s we
know b y v i r t u e of how a d u l t s do it a t i t s b e s t , n o r a s what it looks like
i n i t s ideal text-book forms, b u t a s a s e t of p r a c t i c e s t h a t emerge in a
complex goal-directed c u l t u r a l framework of t h o u g h t , emotion, and action.
Viewed in t h a t w a y , b y analogy to t h e Vai s t u d i e s on l i t e r a c y
p r a c t i c e s , we s e e t h a t programming i s a s v a r i o u s and complex an activity
matrix a s literacy.
J u s t a s o n e mav u s e o n e ' s literacy i n Vai society t o
make l a u n d r y l i s t s r a t h e r t h a n analyze a n d reflect on t h e logical
s t r u c t u r e s of written a r g u m e n t s , s o one may achieve much more modest
activities i n programming t h a n dialectics concerning t h e processes of
g e n e r a l problem s o l v i n g , p l a n n i n g , precise t h i n k i n g , d e b u g g i n g , a n d t h e
discovery of powerful i d e a s .
One may, in p a r t i c u l a r , write l i n e a r
brute-force code f o r drawing i n t u r t l e g r a p h i c s .
Stated b a l d l y , from a functional p e r s p e c t i v e we may see t h a t
powerful ideas a r e no more a t t r i b u t e s i n h e r e n t " i n " Logo than powerful
ideas a r e i n h e r e n t " i n " written language.
Each may be p u t to a b r o a d
r a n g e of p u r p o s e s .
What one does with Logo--or written language--or
any symbol system, for t h a t mattel---is an open r?atter.
One must come
to these powerful i d e a s a n d potentially fertile g r o u n d s for developing
general thinking skills t h r o u g h d i s c o v e r y , o r t h r o u g h learning with t h e
gyidance of o t h e r s .
I n d e p e n d e n t discovery arid practice of Logo
r e c u r s i o n , for example, may b e a v e r y r a r e spontaneous occurrence. T h e
Vai h a v e not s p o n t a n e o u s l y got onto t h e logical f e a t u r e s of written
l a n g u a g e , philosophy, a n d t e x t u a l analysis t h a t written language allows.
Likewise, most of o u r students--from g r a d e school u p t h r o u g h h i g h
school--have not spontaneously got onto t h e programming p r a c t i c e s , s u c h
a s s t r u c t u r e d planful a p p r o a c h e s to p r o c e d u r e composition for reusability
a s building blocks in o t h e r p r o g r a m s , u s e of conditional o r r e c u r s i v e
s t r u c t u r e s , o r careful documentation and d e b u g g i n g , t h a t Logo allows.
For t h e Vai, one could imagine i n t r o d u c i n g new logical and analytic
u s e s of their written language.
Similarly, one could imagine introducing
t o children t h e Logo programming p r a c t i c e s many e d u c a t o r s have taken
f o r g r a n t e d will emerge.
In e i t h e r c a s e , we would a r g u e t h a t without
some functional significance to t h e activities for those who a r e learning
t h e new p r a c t i c e s , t h e r e is unlikely to b e s u c c e s s f u l , t r a n s f e r r a b l e
learning.
Sei-ving some purpose--whether being able to solve problems
one could not otherwise, satisfying an intrinsic interest in complex
problem solving, o r achieving solidarity with a p e e r group who define
their identity in p a r t by "doing" Logo o r written language--is a necessary
condition for the symbolic activities we a r e i n t e r e s t e d in promoting to b e
ones o u r l e a r n e r s find a commitment to.
It is my hunch t h a t wherever we see children using Logo in t h e
ways its designers h o p e d , a n d learning new thinking and problem solving
skills, i t is because someone h a s provided guidance, s u p p o r t , ideas f o r
how t h e language could b e used.
They will have pointed t h e way
through examples, r u l e s , and help in writing programs and discussing t h e
powerful ideas. To call t h e s e rich activities "learning without curriculum"
i s misleading, and a n overly narrow view of what constitutes curriculum,
for any projected p a t h toward g r e a t e r competency that another person
helps a r r a n g e can b e t h o u g h t of a s a curriculum.
There a r e many profound consequences of t h i s more general account
of what is involved in thinking about Logo a s potential vehicle for
promoting thinking a n d problem solving skills.
A functional approach t o
programming recognizes t h a t we need to c r e a t e a c u l t u r e for Logo, in
which s t u d e n t s , p e e r s and teachers talk about thinking skills, display
them aloud for o t h e r s to s h a r e and learn from, a culture that continually
reveals how programming is a vehicle for learning general thinking skills,
and that builds b r i d g e s to thinking about o t h e r domains of school a n d
life.
Such thinking skills, a s played out in programming projects, would
come to play functional roles in the lives of those in t h i s culture. Dialog
a n d inquiry about t h i n k i n g and learning processes would become second
n a t u r e , and t h e development of -general problem solving skills s o
important in an information age would b e a common achievement of
students.
This vision could be realized.
I imagine that important
cognitive effects of programming, o r of literacy a r e possible, b u t only
when certain u s e s of t h e s e symbol systems a r e practiced, not the o n e s
most engaged in today.
T h e r e is f a r too much faith today that Logo
carries with i t g u a r a n t e e s of cognitive outcomes, and I have fears t h a t
when these profound
changes a r e not f o u n d , educators will b e
prematurely discouraged.
Wbere a r e w e left a f t e r these two continents of travel? With t h e
b r i g h t sound of an optimistic chord.
T h e r e a r e many streams of Logo
activities a n d r e s e a r c h t h a t should go o n , for plurality a n d diversity
provide exciting g r o u n d s for emergent ideas.
Communication among
g r o u p s , such a s t h i s forum p r o v i d e s , will help in t h e formation of a
broad community exploring t h e s e issues.
These streams will no d o u b t
embody a diversity of assumptions about what will b e s t help create t h e
culture of Logo I have r e f e r r e d t o , in which one will b e more likely to
find the cognitive effects on thinking skills s o many take for g r a n t e d .
Similar Logo c u l t u r e s may a r i s e t h a t c e n t e r on math learning, o r
programming.
I t is uplifting t h a t t h e r e a r e so many positive energies in education
today.
The enthusiasm for Logo a s a vehicle of cognitive change is a n
exhilarating p a r t of t h e new processes of education one can see emerging.
Cultures with thinking tools like Logo can be created. But we must f i r s t
recognize that we a r e visitors in a s t r a n g e world--at the fringe of
creating n culture of education that takes for g r a n t e d t h e usefulness of
t h e problem solving tools provided by computers, and the kind of
thinking and learning skills that the domain of programming makes so
amenable to using, refining, and talking about together.
.. 7.
Acknowledgements
.'L:
This essay will appear in the Proceedings of t h e Lago 84 MGetlngs,
MIT, Cambridge, MA, June 1984. I would like to take this opportunity to
thank the Spencer Foundation and the National Institute of Education
(Contract #400-83-0016) for supporting our research programs on t h e
development of Logo programming and i t s relation to other cognitive
skills.
My colleagues at the Center fox Children and Technology have
been a continuing source of encouragement and stimulation.
References
Pea, R. D. , % Kurland, D. M. (1983). On the cognitive prerequisites of
learning computer programming.
Interim Report to the National
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