Document one is from Benjamin of Tudela and is the most credible because it is the least biased view and gives seemingly accurate descriptions of the city for outsiders.
Document 2 is written by Robert of Clari, but this document is very biased and is written for the common people to boost their view of the wealth of Constantinople.
Document 3 is written by Nicetas Choniates and describes how the Latins destroyed artwork of Constantinople.  This view is biased, and portrays the Latins as barbarians, so it was most likely written for the people of Constantinople.
Document 4's author is unknown but it is most likely a citizen of Constantinople.  This document is a simple picture of the basic outline of the city, so it could be directed at outsiders to portray the city as large and strong.
Document 5's author is unknown, but it is a picture of the inside of a beautiful church, showing the importance of religion in their society.
Document 6 is written by George Acropolites and this gives details about an emperors trip to Constantinople and the various prayer rituals that took place.  This source is credible as it is written as a historical document to teach others how important religion was in the city.
Document 7 is written by Chrysobull, to explain the relationship between Constantinople and the venetians as positive and largely trade related.  This is written most likely for the public to show the positive relationship they shared with the Venetians.