The following is dated, but information on issues that still apply to morphological tagging:

(Warring: the Bible Software programs mentioned below have evolved, and have a lot more morphological tagged texts than they did back in the 90’s when this was written. Bible Works version 3 and Logos version 2 are discussed below, but both been replaced and updated by newer and more advance versions of their respective programs, several times, throughout the last decade and half. Now, BibleWorks is in it’s 9th version and Logos is in it’s 6th version) 

Researchers who use these tools should be aware of how these potential pitfalls can affect the accuracy of their analysis.

The following discussion focuses on the Greek New Testament, but the principles are applicable to searching the Hebrew Bible and Septuagint.

Differences in the Underlying Biblical Texts

1. Different Morphologically Tagged TextsAs has been shown, there is a considerable variation in the tagging schemes used in Greek New Testament texts. The Friberg texts use a more functional classification method than other texts. Even the Friberg 2 text still has many functional and unusual classifications. The Gramcord and CCAT texts use largely formal classifications.Unfortunately, except for Gramcord, the manuals for popular Bible-search programs rarely discuss the assumptions used in the classification of words. Yet it is essential that researchers understand the nature of the underlying machine-readable biblical text if their analysis of the text is to be meaningful.The print edition of the Friberg 1 text has an appendix outlining the criteria used for the tags (Barbara and Timothy Friberg, eds., Analytical Greek New Testament, Grand Rapids: Baker, 1981). Unfortunately there is no similar book explaining the classification philosophy of the revised Friberg text. In many instances TheWord deviates from the Friberg 1 tags, without documenting the differences. No program makes use of more than one of the Friberg multiple classifications of ambiguous words and no program documents the selection criteria…
2. Many tagged texts have some functional or unusual classifications of words which can produce unexpected search results.In Gramcord, many foreign words such a hosanna are classified as interjections. However, foreign proper nouns are classified as nouns and parsed by function in context. By contrast, Bible Windows and Bible Works classify hosanna as a particle.Conjunctions and particles are particularly difficult words to classify. A beginning user might miss many occurrences of kai if he only searches for the word as a conjunction. Since kai also functions as an adverb in some cases, most programs will sometimes classify it as an adverb. However, as the following chart shows, the classification choices in individual instances vary considerably:

1. Bible Windows was unable to report the total number of occurrences of kai, because it only allows 750 matches in a search. Since it is hard to predict how a program will classify the word in any given passage, the safest approach is to search for all possible classifications and manually eliminate invalid matches. The Gramcord manual documents how many times each word is classified as a conjunction, particle or adverb, which makes it easier to define searches that will find all occurrences of such words.Since the Friberg text (Bible Works and TheWord) attempts to classify many words by function based on discourse analysis, some classifications may be surprising to users. Friberg 1 uses the category of “substantive adjective” to refer to adjectives which are used as nouns in context. For example, agathos (“good”) is classified as a substantive adjective in Mt 5:45 (“he makes the sun shine on the evil and the good). This type of classification affects 4131 occurrences of 1068 words in 3009 verses! While adjectives can certainly function as substantives, the term “substantive adjective” is not a part of speech used by most Greek grammars. It would be easy for a user to accidentally miss many important occurrences of adjectives unless he searches both for “adjectives” and “substantive adjectives”. The Friberg 2 text eliminates the substantive adjective classification, but it introduces other surprising functional classifications. For example, in most cases Friberg 2 classifies relative pronouns as adjectives, with an adjective subtype of “relative.” It introduces a category of participial imperative (168 occurrences of 120 words in 135 verses) and (7813 occurrences of 1726 words in 4792 verses).Functional classifications such as those frequently used in Friberg’s text are more subjective than formal classifications. Their value depends largely on the accuracy of the classifier’s interpretation of the text. While they appear to be objective raw data, in fact they contain the prior conclusions of another researcher, which tends to skew the search results to fit the classifier’s own viewpoint.
2. Treatment of Classification AmbiguitiesEven the strictest formal classification method must classify certain words by function in context, since the morphology of these words is inconclusive. While in most cases the meaning is clear in the context, in some instances the grammatical classification is subject to scholarly debate. For example, the gender of potamou could be either neuter or masculine. In Mt 6:13 the meaning is debated: Does the Lord’s Prayer ask for deliverance from “evil” (neuter) or “the evil one” (masculine)? Since Bible Windows 2, Gramcord and Accordance classify potamou in Mt 6:13 as neuter, a search for masculine adjectives will not find the verse. By contrast, TheWord and Bible Works classify the word as masculine and do not allow the word to be found in a search for masculine adjectives! Only Bible Windows 3 acknowledges both possible parsings and allows the word to be found with either search.Bible-search programs would be more useful if they marked such words as ambiguous and allowed searching on the multiple classifications. The print version of the Friberg text includes multiple classifications in many instances. However, at this time only Bible Windows 3 allows searching on Friberg’s multiple classifications. Although Bible Works and TheWord both remove the multiple parsings in Friberg 1, the documentation does not explain the criteria used to make these choices.Gramcord makes a good attempt at handling ambiguous classifications. In many cases, it tags words in multiple ways and flags the ambiguous classification in the resulting concordance. The documentation lists all ambiguous classifications which are used. However, even Gramcord could be improved in this area. For example, it does not include the ambiguous classification ofpotamou in Mt 6:13.