PSI & A-T Approaches
1) Similarities:  Both approaches emphasize student choice through self-pacing, and personal selection of time for completion of assignments.  Both also stress that instructors must be willing to provide learning opportunities beyond the traditional lecture.  Indeed, lectures are not the primary means of learning in both approaches.  Both strive to establish course and learning objectives and relate subsequent lessons and activities directly to those objectives.

Differences:  The PSI Approach does not tend to promote student interaction, at least within the original structure.  Instead, the student would independently complete supplementary activities at a study carrell.  This can lead to a sense of isolation.  The A-T Approach encourages both large- and small-group interaction.  The A-T Approach does not require a Mastery Grade of 100% like the original PSI.  This "perfection is expected" concept could be discouraging for many students and could lead to frustrating experiences, especially if one scores 99% regularly.  The Mastery Tests of necessity would have to be written in such a way that they are inherently free of any bias, ambiguity or interpretation capability.  This standard would be difficult to attain.

Both approaches share the tenet that students CHOOSE to learn and are not forced to do so.

2) My initial reaction to the PSI was memories, not necessarily fond ones, of high school Trigonometry class.  My teacher used this method of progression by mastery.  I always managed to fail the first unit test and then pass the second.  However, one unit required 7 tests to "master".  This mastery actually meant that I memorized problems from prior tests.  I did not know the content well but eventually I received an acceptable score.  I see this as a potential barrier in that current content may not be related by the student to prior content.  The course becomes an exercise in passing small chunks as opposed to trying to discern the overall "big picture".

My initial reaction to A-T was that it needed to be updated, as audiotapes are not necessarily the most effective means to convey supplemental material.  They appeal primarily to auditory learners to the exclusion of other types.

If students are able to use multiple learning styles and see the course as a whole, not as a random collection of unrelated smaller units, learning will be more effective and retained better.

3) I anticipate teaching adults in distance education settings.  I would be more likely to use the A-T method, with some upgrading of media.  The courses I would teach are more training-oriented, so the PSI "progression by perfect mastery" would not necessarily be applicable.  Classes are rarely so long as to require multiple units over extended time spans.  I could anticipate using the A-T GAS at the start and requiring participants to complete an ISS as a prerequisite.  At each work site, assuming there are multiple students per site, the SAS would be the heart of the educational process. 

4) I would anticipate the use of systems such as Blackboard, Elluminate, or WebEx would be helpful, especially in distance learning settings.  Discussion boards and chats would also encourage collaboration, as would wikis. Even a virtual reality program such as Second Life could be used for the SAS function, though it would be difficult to do.