During the time that Jesus disciples waited for the outpouring of the Holy Spirit, they took upon themselves the task of selecting someone who would take Judas' place. Peter put forth the criteria that the person must meet.They had to have been with the rest of the disciples "from the baptism of John" to the ascension of Jesus.
The two men whose names were brought forth as candidates who met the criteria were Barsabbas and Matthias. These men were not then voted upon as if this were an election. No, the disciples asked God to choose which one was to be added to the eleven. After asking God in pray to choose, the disciples drew lots and the lot fell to Matthias who was then added to the eleven.
The selection of who is to serve in positions of leadership is a serious matter and is not to be taken lightly. This is discussed in this message.
Also discussed, is the phenomena of speaking in tongues and when the speaking in tongues is to be interpreted.