Here is another interesting thought from James D.G. Dunn on the Apostle Paul’s pneumatology. This time he focuses on Paul’s understanding of the gifts of glossolalia and prophecy:
Paul envisages conversion (to the Spirit) as an unveiling, evoking the experience of a veil being removed, of eyes being opened. Any university teacher, and, hopefully, all university students, know the experience all too well. It is quite characteristic of Paul’s conception of the Spirit to link it with experiences of revelation and knowledge. Particularly notable is 1 Cor. 2.12–“we have received…the Spirit which is from God, in order that we might know what has been given to us by God.” And it is worth noting that the reason why Paul preferred prophecy to glossolalia in the gatherings for worship was because prophecy was fruitful for the mind as well as the spirit (1 Cor. 14.14-5).
Implied in Dunn’s statement is that glossolalia was not understood to be valuable in public worship because it could not be understood and therefore it does not edify others. Glossolalia is limited to self-edification. Prophecy edifies the speaker and hearer.
the archives near Emmaus 
Brian,
I think it is important to note that Paul’s preference for prophecy is specifically in the context of corporate assembly/worship. His primary concern for coporate assembly/worship was corporate edification, which is why he prefered prophecy to uninterpreted tongues. He saw prophecy and interpreted tongues as equally valuable, however, since both resulted in corporate edification.
Jason
Yes, it is in the context of assembled worship. But this is a side note since most of the gifts are not given for the dual purpose of self and corporate edification (e.g. One would probably not “prophecy” to oneself). It actually takes two gifts in tongues and interpretation to match one in prophecy as concerns value in a corporate setting.
I agree with your observations. But the point needs to be made because it is lost on so many non-Pentecostals (and even some Pentecostals). They conclude, based on Paul’s comments, that he considered prophecy to be a superior gift to tongues. But that is not what Paul says. It’s clear that his preference for prophecy over tongues is specific to a given context, not a general preference. Indeed, as you have pointed out, in the context of one’s private prayer life, prophecy is of no value, while tongues is of immense value. The gifts that are most important is highly context-dependent. If my leg is broken in half in a car accident, the most important gift is not prophecy, but the working of miracles!
Jason