Lajoie, S. and Lesgold, A. (1989). Apprenticeship Training in the Workplace: Computer-Coached Practice Environment as a New Form of Apprenticeship
Summary by Lyman Taylor
SHERLOCK is a Computer-Coached Practice Environment that provides
apprenticeship training ( as defined by Collins and Brown ) for a
complex skill ( namely electronic test station troubleshooting ).
Computer-Coached Practice Environments provides opportunities for
practicing cognitive activity in a realistic setting, which computer
supplied support when needed or asked for. There is an implied
emphasis on the "realistic setting" part. The students are to
engage in problem solving in an environment that is largely identical
to their normal "real world". This environment provided also includes
not just the "physical" manifestation of the problem to be solved but
also a computer substitute for an expert problem solver who is
there to answer questions.
The following is a discussion of:
The Goals of SHERLOCK
Why use Technology?
What does SHERLOCK look like / how does it work?
Results / Future Work
Why is SHERLOCK successful?
1. Goals of SHERLOCK
SHERLOCK is an implementation of a "new apprenticeship" model for the
instruction of a cognitive skill ( see. Collins and Brown ). This model
should exhibit the following:
o Learning is situated in a social context similar to those
in which the skills will be used;
o Both novice and master are active participants in the
o Cognitive processes are externalized and displayed for
So in reality SHERLOCK really has two distinct subcomponents. One is the
facilitation of the learning environment. The other is playing the role
of the master. To be effective the distinction between these two blurs when
you look at the implementation.
SHERLOCK has two target "users".
SHERLOCK provides an environment in which to learn the skill of
troubleshooting test equipment. The hope is to produce students that
that have "operational knowledge". As opposed to "inert knowledge"
( i.e. knowledge of the "facts" but without the skills to
operationalize these "facts").
SHERLOCK provides two things for a researcher.
i. a means of measuring the effectiveness of this "new apprenticeship"
model in an environment that would be very difficult to
duplicate in a traditional Air Force job shop.
ii. to investigate the aspects of the role of the master/expert; such
When should coaching be provided and when should it be
How can coaching be individualized for a student?
obviously these two "measurements" cannot be decoupled.
2. Why use Technology?
SHERLOCK has several advantages over what can be accomplished in the normal
Air Force job shop.
i. SHERLOCK can coach many students at one time. In a typical job
shop the student expert ration is far from one to one.
Since the instruction is one-on-one the instruction may be
specifically tailored to the individual.
ii. SHERLOCK provides an environment which is more conducive to
learning that utilizing the real test equipment.
a. failures that only occur rarely in the the "real world"
are readily produced.
( failures of test stations are rare. )
b. a wide variety of failures may be produced.
( failures of test stations are diverse, but rarely
occur in instructionally optional sequences).
c. inexpert troubleshooting on a simulated test station will
not damage it.
d. inexpert troubleshooting of a test stations is very
time consuming. SHERLOCK facilities removing the
"time pressure" component by providing support and
by not occupying a test station that someone else
3. What does SHERLOCK look like / how does it work?
SHERLOCK has the following components
SHERLOCK's knowledge is organized around problems, solutions methods,
and the constraints imposed on problem solution by the structure of
the work environment. This knowledge is represented in specialized
structures that are specialized to each problem that is being
Teaching involves presenting complex procedures for the student to
learn from. When the student cannot handle the problem as a whole,
support is provided for the portions that are problematical.
Advice if often given only on demand.
The student model is used to control:
i. when expert advice needs to be given. And to tailor
advice when asked for.
ii. to adapt the presentation of problems and their complexity
to the student's level of competence.
iii. to fade hinting and support as trainee skill develops.
SHERLOCK provides help by producing a template for cognitive skills.
It can present the student's plan under control of the student.
If the student becomes "hopelessly lost" he may press a panic button
to see his plan ( or at least SHERLOCK's interpretation of what
his plan should be ).
4. Results /Future Work
Students using SHERLOCK should increased proficiency in troubleshooting
test stations above that of students not using the system. Students who
spent twenty to twenty-five hours working with SHERLOCK were as
proficient as technicians who had been on the job four years longer.
i. SHERLOCK does not allow for role reversal.
ii. Interaction with SHERLOCK's externalization of problems could be
iii. A video-disc could be used instead of computer graphics.
5. Why is SHERLOCK successful
The authors believe that a successful training environment should follow
1. Teach specific domain knowledge along with metacognitive skills
and heuristics that leverage the domain knowledge.
2. Embed learning with a problem-solving environment that reflects
the uses to which knowledge will be put.
3. Provide opportunities for learning through a combination of guided
practice and locally situated opportunities for observation.
4. Emphasize holistic procedural training. ( i.e. don't train on
"baby problems" and scaffold when necessary. ).
5. Train the specific competence required rather than training
6. Cognitive task analysis of the hardest thinking tasks in a job are
critical to success.
7. Build from the highest level of domain expertise. ( i.e. model the
experts in the domain. NOT the domain ).
8. Enable the development of complex subgoal structures.
9. Adapt instruction.
[ This isn't in the paper... ]
I think the ramifications on teachers would fall into three categories.
i. For domains where either one-to-many interactions is difficult the
the teacher's job becomes the "person" to which a student
escalates a problem to when a SHERLOCK system fails.
ii. For domains in which a "expert" is not available. this type of
system is helpful. Teachers can't know everything.
iii. For domains which are dangerous. "John in the back of the
room with the Bunson burner... " the system is also helpful.
However to solve complicated problems you still have to have some "facts"/
skills with which to use. The teacher imparts these and the SHERLOCK
environment helps them operationalize them.