Metaphor: The calculator--

A "black box."

When you press the + key, it activates part of the program that adds
two numbers.

€ First microprocessor: developed for use in a calculator (1971, Ted Hoff
at Intel).

To change the calculator‹just change its program.

Destroyed the market for mechanical calculators.--

Familiar Microworlds--

€ Microworlds: computer models of familiar processes.

Example: The word processor began as a typewriter with memory.

€ Applications acquire capabilities that didn't exist before.

For instance:
Changing typefaces in the middle of a document

€ The spreadsheet began as a model of an accountant's ledger sheet.

This microworld has more capabilities than a ledger:

€ User-configurable program: smart data--

The State of the Art--

€ Many applications, tailored to specific tasks.

Business

Accounting, tax preparation, stock forecasting, inventory control,
smart cash registers, desktop publishing . . . .

And, particularly, database programs:

Numerical Applications

€ Designing and simulating the behavior of aircraft,
predicting weather, enhancing images.

Plot data and fit the data to an equation (simple, but
tedious, numeric calculations)

Perform symbolic algebra:

Example: Given x2 - y2 + x3 y - x2 y2 - x y3 + y4

The program factors it: (x + y) (x - y) (1 + x y - y2)

€ There are programs for personal computers that can do B+ work or better
on freshman calculus exams (!)

The Professions

- Expert systems for doctors, lawyers

- Architects and engineers have sophisticated design programs (CAD)

CAT scans (Computerized Axial Tomography)

Program reconstructs the image.

Benefits: Higher resolution pictures, less X-ray exposure for patient.

Education

€ Early attempts at CAI (Computer Assisted Instruction) were dismal.

- Required hundreds of hours of programming for each hour of session, so. . .

- Were largely limited to simple drill-and-grill

Designing a lesson with DISCUSS:--

Implications--

€ Deskilling: "Computer applications will destroy the next generation's
fundamental skills."

€ Productivity: "Computer applications invariably increase productivity."

€ Information Technology: "Ready access to electronically stored
information will benefit us all."