The right to trial by jury for criminal offenses is provided for in the Constitution. However, over the years the Supreme Court has struggled with questions concerning the meaning of certain phrases, such as 'all crimes,' 'all criminal prosecutions,' and 'jury.' Decisions dating from the late 1880's shaped the concept of trial by jury as it exists today. In the 1970 ruling in 'Baldwin v. New York,' the Court examined the criteria to be used in determining whether a crime may be deemed petty. In the landmark case of 'Ballew v. State of Georgia,' (1978) the Court found that the five-member jury did not satisfy the jury trial guarantee of the sixth amendment. Further clarification of the issue came in the 1976 holding of 'Williams v. Florida.' In that case, the Court held that the number of jurors required is only that number which is necessary to promote group deliberation, to insulate members from outside influence and intimidation, and to provide a fair chance of having a representative cross section of the community. The Court conjectured that there was no discernible difference between the results obtained by two different sized juries, basing its conjecture upon the few experiments that had been conducted at the time. It is contended herein that the Court erred; discernible differences can be identified. For example, there is a significant increase in the likelihood that a minority would not be represented on a six-member jury. The likelihood of representation by minority members on a smaller jury can also be applied to analyzing the likelihood of obtaining a hung jury in any particular case. Anyone familiar with statistics knows that variability of a sample increases with a decrease in the sample size. Other factors which must be considered include likelihood of conviction with smaller juries, effects of size on consistency, balancing of errors, behavioral considerations, and the jury as a reflection of the community. It is suggested that any differences in result which are attributable to jury size may be constitutionally unacceptable. Five tables and 81 footnotes are included in the article.