IN some Bibles yes interpret and translate are different. Many newer Bibles admit they are more interpretations
It seems there are 2 general theories or methods of Bible translation.
1. Formal Equivalence: as much as possible a word for word translation from one language to another
2. Dynamic Equivalence: a thought for thought translation. This requires first an accurate formal equivalence or what you come up with in the dynamic equivalence will be off. The goal iis to be both accurate and understandable.
Many people consider the King James to be accurate but it isn't how we talk and therefore not that great a translation anymore.
My copy of the New Living Translation compares three verses 1 Kings 2:10
King James Version (KJV): So David slept with his fathers, and was buried in the city ofDavid.
New International Version (NIV): Then David rested with his fathers and was buried in the city of David.
New Living Translation (NLV): Then David died and was buried in the city of David.
The thought "slept/rested with his fathers" is translated into "died" which better expresses the real meaning of the expression "slept with his fathers"
Now here is an interesting issue:
The WTS doesn't tell us who their Translation committee is.
NLB website has a list of the scholars who were on the translation team.
NIV lists the people on their committee http://www.niv-cbt.org/translators/
KJV even has a list of the translators from the year 1604 http://www.av1611.org/kjv/kjvhist.html
Wikipedia has referenced some quotes from WT literature regarding the translators http://en.wikipedia.org/wiki/New_World_Translation_of_the_Holy_Scriptures
The New World Translation was produced by the anonymous New World Bible Translation Committee, formed in 1947. This committee is said to have comprised unnamed members of multinational background.  The New World Bible Translation Committee requested that the Watch Tower Society not publish the names of its members,   stating that they did not want to "advertise themselves but let all the glory go to the Author of the Scriptures, God,"  adding that the translation, "should direct the reader... to... Jehovah God".  The publishers believe that "the particulars of [the New World Bible Translation Committee's members] university or other educational training are not the important thing" and that "the translation testifies to their qualification".  Former high ranking Watch Tower staff have claimed knowledge of the translators' identities.  
education isn't important???
Another interesting issue:
The NLB that I mentioned above takes 4 large pages so explain where they got their original texts from and how they went about arriving with their translation. The NIV has 3 pages of small print explaining how they arrived at their translation. The KJV doesn't have it in the Bible but does have it online (see link above for KJV) Even my Good News Bible (GNT) has 3 pages to explain how they came up with their version. (The GNT) is a Dynamic Equivalence translation
On the other hand I can't find anthing in my 1978 copy of NWT regarding where or how they came up with this translation. Wikipedia (above link) was able to find some info gleaned from WT publications:
According to the Watch Tower Society, the New World Translation attempts to convey the intended sense of original-language words according to the context. The New World Translation employs nearly 16,000 English expressions to translate about 5,500 biblical Greek terms, and over 27,000 English expressions to translate about 8,500 Hebrew terms. Where possible in the target language, the New World Translation prefers literal renderings, and does not paraphrase the original text. 
The master text used for translating the Old Testament into English was Kittel's Biblia Hebraica . The Hebrew text, Biblia Hebraica Stuttgartensia (1977), was used for updating the footnotes in the 1984 version of the New World Translation. Other works consulted in preparing the translation include Aramaic Targums , the Dead Sea Scrolls , the Samaritan Torah , the Greek Septuagint , the Latin Vulgate , the Masoretic Text , the Cairo Codex , the Codex Petropolitanus [disambiguation needed] , the Aleppo Codex , Christian David Ginsburg 's Hebrew Text, and the Leningrad Codex . 
The Greek master text by the Cambridge University scholars B. F. Westcott and F. J. A. Hort (1881) was used as the basis for translating the New Testament into English. The committee also referred to the Novum Testamentum Graece (18th edition, 1948) and to works by Catholic Jesuit scholars José M. Bover (1943) and Augustinus Merk (1948). The United Bible Societies' text (1975) and the Nestle-Aland text (1979) were used to update the footnotes in the 1984 version. Additional works consulted in preparing the New World Translation include the Armenian Version, Coptic Versions, the Latin Vulgate, Sixtine and Clementine Revised Latin Texts, Textus Receptus, the Johann Jakob Griesbach's Greek text, the Emphatic Diaglott, and various papyri. 
After reading all this I feel a lot more comfortable with my NIV and NLV Bibles than I do with a NWT