Block also refers to the descriptive coarseness of the "Big Five." Block's article has created much debate on this subject. A useful study that counters many of arguments put forward by Block is Solid Ground in the Wetlands of Personality: A Reply to Block by Costa and McCrae (1995). In contrast to Block's critique, this article suggest that, "...the most impressive achievement of the FFM is its reduction of conceptual jangle, showing how constructs ostensibly as different as absorption, intuition, and need for change all reflect aspects of the single, broader construct of Openness. " (Costa and McCrae, 1995).

The validity and acceptance of the FFM model and the various aspects that are open to discussion and debate are discussed in an article by DeYoung et al. (2007) entitled, Between facets and domains: 10 aspects of the Big Five. The article refers to the levels of the hierarchy above the Big Five domains, as well as the 'facets' at a second level. The authors state that insufficient attention has been given to a level of trait organization located between facets and domains.

One of the most significant critiques, or rather amendments, of the five-factor model is the three-factor model of personality suggested by H.J. Eysenck. Eysenck criticizes the five-factor model on the grounds that there are overlaps in the five factors as well as in their correlates and suggests that a three factor model would be a more appropriate and correct assessment of personality. (Eysenck, 1991, p. 775) as already noted, this critique led Eysenck to suggest the PEN model, which posits the factors of psychoticism, extroversion and neuroticism. Eysenck states that, "Factor analysis has improved the situation...but the problem of naming factors is of course still with us" (Eysenck, 1991, p. 775).

A further criticism of the five-factor model is that although it is both categorical and taxonomic in structure, it does not penetrate deeply enough into the causative aspect of certain correlates. In a study by Davis and Millon, (1993) the view is suggested that the lexical approach of the Big Five assumes that the majority of the "...socially relevant and interpersonally salient personality characteristics have become encoded in the natural language" (Davis & Millon, 1993, p. 105). However, the study by Davis and Millon suggests that, "...convergence is not truth, and convergent validity is not construct validity" (Davis & Millon, 1993, p. 105). In other words, judgment and assessment related to personality factors can converge without necessarily being correct. In this light, the five-factor model is described as being "trivial" (Davis & Millon, 1993, p. 105).

An article by Clark (1993) also explores the limitations of the five-factor model. Clark argues against the categorical model of personality. The author also points out that there is the danger of stereotyping in the five-factor model and in other categorical diagnoses. (Clark, 1993, p. 100)

Another critique of the five-factor model is suggested by McAdams (1992). Central to this critique is that the five-factor model does not qualify as a "great' or fully comprehensive theory. McAdams states that while the five-factor model provides a functional basis for the personality traits in psychology, it however falls short of a truly unified psychological theory. (McAdams, 1992)

The above review of some of the more cogent areas of the literature on this subject leads to the conclusion that while the theory has attained a certain degree of acceptance and viability in psychological praxis, there are also many areas and aspects of the model that have been subjected to criticism and scientific interrogation. This does not imply that the model has less value. On the contrary, the degree and the extent of the debate on this model of personality is a sign of the healthy discourse that it has engendered, which is also an indication of its ongoing relevance in the understanding of personality structure and categories towards the therapeutic understanding...

While claims of a 'perfect' model or theory are questioned by some there is little doubt that, as Digman states, the five variables that compose the five-factor model "...provide a good answer to the question of personality structure" (Digman, 1990, p. 436).