In "Horizontal Phonics," the method most often used by public and private schools, students are initially taught  only one sound for each phonogram.  

Vertical phonics is easier to teach, requires less memory skill and is in consonance with the Associative Principle of Memory i.e. "Teach together, what belongs together."

For example:

It is obviously wrong to teach first the first names and several months later the middle or last names of our presidents.  But that is similar to what "horizontal phonics" instructors do when they teach the alternate possible sounds of a letter or letter combination at different times.

Teaching the names of the presidents, we teach the first, middle (if used), and last names at the same time.

This makes sense and is comparable to "vertical phonics" and the Associative Principle of Memory.

The advantages of TATRAS Vertical Phonics are:

1. Sound-phonogram relationships are memorized and retrieved easier,

2. Learning of confusing diacritical marks and linguistic terms ("long" & "short" sounds) are postponed until later grades where they are more easily taught.

3. Use of third sounds of phonograms reduces number of irregular words,

4. Science of probability is put to work for the student—he is taught which sound to try first,

5. There are few special decoding rules, and,

6. Vertical Phonics can be used, exactly as first learned, until the older student recognizes almost all words instantly.

There are other phonics methods.  Go to:  Methods of Teaching Phonics (Cont'd)