top-down bottom-up

D

Duane Hookom

"Top-down" is a convertible car with nothing above your head and bottom(s)-up
is having a drink ;-)

Could you put your question in some kind of context?
 
C

castle

I am designing a small database from normalization to the interface. the
exact question is "when designing your solution to the problem presented, you
had the option of applying either a top-down or bottom-up solution. Discuss
the two methods and outline why you selected the one you did".
 
D

Duane Hookom

You might not get full credit for this answer but it should get some points
for being clever.
 
J

James A. Fortune

castle said:
I am designing a small database from normalization to the interface. the
exact question is "when designing your solution to the problem presented, you
had the option of applying either a top-down or bottom-up solution. Discuss
the two methods and outline why you selected the one you did".
Click to expand...

Great question. I'll try to explain this and you can derive your own
answer from my description if it applies to your understanding of the
question.

First let me explain what "top down versus bottom up" means to an
engineer. Students start out learning "bottom up" analysis, which means
starting from one or more general principals such as a free-body diagram
or the Conservation of Mass Equation, applying specific conditions
appropriate to those general equations and getting a closed-form
equation(s) or differential equation(s) that encapsulate the physics of
the mechanism(s) or of the process. In this context, "top down" means
starting with an abstract set of differential equations derived from
general principles that are applicable to a wide class :) of problems
and using the specific boundary conditions to pinpoint the solution. An
example of this is the Navier-Stokes equations for fluids. The "top
down" approach is much more abstract and came after a lot of people had
a lot of experience solving lots of problems.

Realize that the following is only my guess at what your instructor is
trying to ask.

When I design a database in Access I start "bottom up" with the obvious
parts of the schema and then after most of it is in place I switch to
"top down" by imagining how the database is going to be used and
maintained. This process usually shows me anything I omitted from the
schema before I start coding. As you get more experience you will
probably move more and more of the process to "top down." Riker in
STTNG, possibly based on the amount of his experience, was advised to
start at the top and work his way down :).

James A. Fortune
[email protected]
 
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