There are several kinds of inaccuracy when we define translation accuracy as the degree to which a specific individual, or social group, understands the meaning of a translation wording the same as the meaning of the biblical source text wording behind that translation. (Or, we can move the bar forward one step, and say that the understood meaning of a wording is the same as the meaning intended by the translators who wrote that wording.)
A translation is not simply accurate according to how Bible translators understand the meaning of the biblical text and how closely they believe their translation wording aligns with that. We must also consider that a translation is made for others, people who do not understand the biblical languages, so that they can understand the Bible in their own languages and dialects. Different sociolinguistic groups use different vocabulary and even some different syntax, even though they speak the same overall language. Bible scholars, who work closely with the biblical languages and who are familiar with "church language" are able to understand certain kinds of wordings in Bible translations more easily than can individuals who are less familiar with traditional church language. A Bible translation may be accurate for scholars, but not accurate for non-scholars, if the non-scholars get wrong meanings from translation wordings written in the language which scholars understand.
What, then, are some kinds of translation inaccuracies possible in Bible translations?
1. Exegetical inaccuracy: the translation wording does not align with the meaning of the source text (or at least the meaning as understood by many biblical scholars). There are several different categories of exegetical inaccuracy, including:
a. Wrong meaning: In the GW (God's Word) translation of Phil. 4:5 we read "Let everyone know how considerate you are." I understand this wording to be inaccurate because we are not to let everyone know how considerate we are, but, rather, to be considerate to everyone. The GW wording sounds like we are to brag about how considerate we are. I am sure that the GW translators intended a different meaning. The problem here is that there is not much difference in English wording between traditional (and accurate) wordings of this verse, such as ESV "Let your reasonableness be known to everyone" and the GW wording. (Other versions substitute "gentleness" or "forebearance" which are very close in meaning.) "Let (something) be known" and "Let everyone know (something)" are close in wording but have an important meaning difference where the more passive "Let it be known" does not require that you make something known by speaking about it or in some other way pointing to it. But "Let everyone know ..." does communicate the idea of an active speaking about something or in some other way pointing to it.
b. Omission of meaning: leaving out some meaning of the source text. CEV Acts 14:23 states "Paul and Barnabas chose some leaders for each of the churches. Then they went without eating and prayed that the Lord would take good care of these leaders." The meaning of the Greek eis hon pepisteukeisan 'in whom they had believed' is missing in the CEV wording of this verse.
c. Addition of meaning: adding some meaning which is not in the biblical text. Ron Gordon points out on his webpage Translations Compared that there is added meaning in NLT Acts 27:14 "But the weather changed abruptly, and a wind of typhoon strength (a “northeaster,” they called it) caught the ship and blew it out to sea." Ron notes that the phrases "caught the ship" and "blew it out to sea" are insertions, not supported by the Greek of Acts 27:14.
d. Zero meaning: where a translation wording communicates no meaning to its users. This can occur from the use of an archaic word that no longer has meaning in the target language, or from unnatural word combinations or imported syntax. Some current users of English Bibles do not know the meanings of some of theological terms which were borrowed into English from Latin words used in the Latin Vulgate, words such as "propitiation," "expiation," "justification," and "sanctification." The meanings of these words can, of course, be taught to those who do not know them. On the other hand, having to teach people the meanings of words in a Bible translation to some extent defeats the purpose of a translation which is to allow those who do not understand the Bible in its original language to undersand it in their own language. But there are audiences and situations for which use of traditional church language is important in Bibles. Such usage can help make a Bible sound "dignified" or that it is truly a "church book" to people who are accumstomed to hearing such words.
There are other kinds of zero meaning possible in a Bible translation. One is where a biblical idiom or metaphor is literally translated but its literal translation does not communicate the biblical meaning to its users. As always, we must remember that there are different audiences that use a translation, so there will likely be some audiences which have been taught the meanings of such literally translated idioms or metaphors. But some people prefer to know the meanings of unfamiliar wordings from a translation itself or they may not be in an environment where they can learn their meaning through teaching. For such people it can be best not to translate idioms or metaphors with zero meaning. The KJV wording "shutteth up his bowels [of compassion] from him" (1 John 3:17) has no (zero) meaning to most English speakers today. That is why recent English versions translate the figurative meaning of the Greek metaphor "bowels of compassion" with meaningful wordings such as "closes his heart against him" (RSV, ESV) and "have pity on that person" (CEV).
2. Collocational inaccuracy: where a word combination, often not natural in the target language, communicates a different meaning to speakers of a language from the meaning intended by the translators. ESV 2:24 is worded as "a wild donkey used to the wilderness, in her heat sniffing the wind! Who can restrain her lust?" The phrase "in her heat" in English refers to a stage of a track event, as in the sentence, "She got third place in her heat for the 100 meter hurdles." The ESV translators did not intend to communicate this meaning with the words "in her heat," but that is what those words mean in English. (Yes, I realize that a reader should catch on that a different meaning is intended for these words from the context of Jer. 2:24, but the words "in her heat" are, nevertheless, inaccurate for communicating the intended meaning.) What is the intended meaning? It is surely "in heat." In English, some female animals are said to be "in heat" during part of their menstrual cycle.
3. Language change inaccuracy: In Rom. 14:17 the KJV is worded "For the kingdom of God is not meat and drink; but righteousness, and peace, and joy in the Holy Ghost." The word "meat" apparently was an accurate translation in Elizabethan English spoken when the KJV was translated, referring to more than just the flesh of animals, but, rather to food in general, which is the meaning of the underlying Greek word brosis. Recent English versions accurately translate brosis to words such as "food" or "eating". Please note that we are not saying that "meat" is an inaccurate translation in the KJV. It is only inaccurate for those English speakers who no longer have the meaning sense of 'food'. This would include the majority of English speakers today.
4. Syntactic ambiguity: Unintended target language syntactic ambiguities can create inaccurate understandings when translators are not aware of the multiple meanings created by their wording. The Hebrew of Jer. 2:25 ends with words which should communicate in English the meaning that Israel persists in following the idolatrous ways (or gods) of foreigners ("strangers"). One way of expressing this idea is to say "follow after them" (where "them" can refer either to the foreign gods or the ways of the foreigners which would include worship of their gods). I think the wordings "follow after" or "go after" communicate the Hebrew meaning accurately to most English speakers--in this case "after" functions as a particle, part of the verb, rather than as the preposition in a prepositional phrase "after them." But notice that syntactic ambiguity is created in English when "after" is moved to the beginning of the clause. This ambiguity was created by the RSV translators (and retained by the NRSV and ESV translators; the problem also occurs in the KJV, NASB, NJB, and the Tanakh) who use the wording "after them I will go." It is possible for the correct meaning (that of pursuing them, or following in their ways) to be gotten from this wording, but it seems to me even more likely for someone to get the wrong meaning from it, namely, that the "I" of the passage will succeed "them" in time. The ambiguity is largely removed and there is improved accuracy in those English versions (e.g. REB, NIV, TNIV, NLT, TEV, NCV, CEV, NET, HCSB) which use the more normal English word order for the meaning of chasing someone, e.g. "will go after them" (TEV) and "will continue to follow them" (HCSB).
There may be other categories of inaccuracy which I have not included in this post. Can you think of some? If so, please mention them by clicking on the "comments" link below this post.