The graphical powers of Microsoft's Windows 3.0 brings its users a new dimension in software that lets you see on the screen just about what you'll get when you print.

That change is especially dramatic in word processing, where users of IBM and compatible computers, unlike their Macintosh counterparts, usually have had to be content with seeing plain, text-only renditions of documents. The type on the screen always looks the same whether or not various sizes and styles of type are called for in the printed document.

The two powerhouse word-processing programs for Windows 3.0 are Microsoft's Word for Windows, $450, and Samna Corp.'s Ami Professional, $495.

Word for Windows is geared to high productivity in office word processing, from simple memos to complex legal briefs. Its power comes from a set of automated templates that allow material to be placed exactly where you want it in your document. For instance, fill in just a few blanks in the legal brief template and the entire top of the brief will be properly formatted with names of plaintiffs and defendants, case number and type of action.

Ami Professional lacks the automated features, but lets you draw geometric objects in your documents and create charts, neither of which are features offered in Word for Windows. It also allows some modification of imported graphic images, such as scanned-in pictures, which makes the program more akin to desktop publishing software.

Both programs have all the features of traditional word-processing software, such as a spelling dictionary and thesaurus plus the ability to create tables of contents and indexes, outline, footnote and annotate text.

Each program also allows you to create tables within a document. The tables can be a mixture of text and numbers, and basic math can be performed on the numbers. Of course, for heavy-duty number crunching you would rely on spreadsheet software, and both of these programs can link to spreadsheet files in a variety of ways.

The way text looks on your screen and on paper is controlled in both programs by "style" sheets that can define all the variables from margins to the size and style of the type.

Seeing the same type on screen as you will see on paper is not always beneficial. None of the screen fonts are as crisp as the standard character set that comes on IBM and compatible computers. Thus the letters on the screen tend to be thinner than what you see with a traditional text-based word-processing program like WordPerfect or WordStar.

And, depending on the font being used, the letters can be squeezed so closely together that words are hard to read and even harder to check for errors. If you primarily write long articles or books and need only produce a legible manuscript, a text-based word processor would probably be easier to use.

However, for general office word processing these programs can be a great help. For instance, if you don't need fancy embossed stationery or letterheads printed in some color other than black, you can use either Ami Professional or Word for Windows to print the letterhead when it prints the text of the letter.

For many users, either program would be satisfactory. Both are powerful and thus quite complex. Learning how to use all of the features is a major undertaking. For example, the way each program looks on the screen and the choices of items listed in their menus can differ according to the user's wishes. That means it is easy to get lost, especially in the beginning when you can't find the menu choice you want because it isn't currently in the lists you are using.

Ami Professional gets the nod for users who need to draw objects in their documents, such as simple organizational charts, or to call attention to certain paragraphs of text. The same is true for those who need charts, although it is easy enough to import an Excel chart into Word for Windows.

Word is the more powerful of the two, both in the richness of its macro language that allows you to automate tasks and in its smart templates. The templates included with the program are amazing in the way they can simplify creation of complex documents.

I would think that law offices in particular would benefit. But, although you can use the templates just as they come out of the program's box, they aren't of any use until you have modified them to reflect your own needs. Modifying them is not too hard, but it is not a task for beginners. Somebody in the office must become an expert before you can get much use out of the automated features.

Richard O'Reilly is a Los Angeles Times staff writer. Readers' comments are welcomed, but the author cannot respond individually to letters. Write to Richard O'Reilly, Los Angeles Times, Times Mirror Square, Los Angeles, Calif. 90053.