This paper describes the derivation of an updated statistical catalog of metallicities. The stars for which those metallicities apply are of spectral types F, G, and K, and are on or near the main sequence. The input data for the catalog are values of [Fe/H] published before 2002 February and derived from lines of weak and moderate strength. The analyses used to derive the data have been based on one-dimensional LTE model atmospheres. Initial adjustments which are applied to the data include corrections to a uniform temperature scale which is given in a companion paper (see Taylor 2003). After correction, the data are subjected to a statistical analysis. For each of 941 stars considered, the results of that analysis include a mean value of [Fe/H], an rms error, an associated number of degrees of freedom, and one or more identification numbers for source papers. The catalog of these results supersedes an earlier version given by Taylor (1994b).

High-dispersion and low-resolution data are combined to search for super-metal-rich (SMR) FGK stars in the solar neighbourhood and Baade's Window. The data are assessed by using statistical analysis, with their rms errors playing a key role. A star is considered to be SMR if its value of [Fe/H] > +0.2 dex, while 'borderline' SMR status may be assigned if +0.1 < [Fe/H] &LE; +0.2 dex. Borderline SMR status is assigned to μ Leo and three other giants, but no full-fledged SMR giants are found in either Baade's Window or the solar neighbourhood. By contrast, the existence of SMR class IV-V stars turns out to be well established, with values found for [Fe/H] that are as large as &SIM; +0.4 dex. It is concluded that this apparent contrast between class IV-V stars and giants should not be interpreted in astrophysical terms at present because of marked shortcomings in the available data base for giants. Recommendations are made about future research that may cure this problem and extend present knowledge about SMR dwarfs.

For the often-studied "SMR" giant mu Leo, Smith & Ruck (2000) have recently found that [Fe/H] similar to +0.3 dex. Their conclusion is tested here in a "statistical" paradigm, in which statistical principles are used to select published high-dispersion mu Leo data and assign error bars to them. When data from Smith & Ruck and from Takeda et al. (1998) are added to a data base compiled in 1999, it is found that conclusions from an earlier analysis (Taylor 1999c) are essentially unchanged: the mean value of [Fe/H] similar to +0.23 +/- 0.025 dex, and values less than or equal to +0:2 dex are not clearly ruled out at 95% confidence. In addition, the hypothesis that [Fe/H] greater than or equal to +0.3 dex which emerges from the Smith-Ruck analysis is formally rejected at 98% confidence. The "default paradigm" which is commonly used to assess mu Leo data is also considered. The basic characteristics of that paradigm continue to be a) unexplained exclusion of statistical analysis, b) inadequately explained deletions from an [Fe/H] data base containing accordant data, and c) an undefended convention that mu Leo is to have a metallicity of about +0.3 dex or higher. As a result, it seems fair to describe the Smith-Ruck application and other applications of the default paradigm as invalid methods of inference from the data.

For the old galactic cluster NGC 6791, Peterson & Green (1998a) and Chaboyer et al. (1999) have found that [Fe/H] similar to +0.4 dex. A second look at that conclusion is taken in this paper. Zero-point problems are reviewed for a high-dispersion analysis done by Peterson & Green, and it is found that accidental errors have not been determined rigorously for the results of that analysis. It is also noted that in a color-magnitude analysis performed by Chaboyer et al., the important metallicity range between 0.0 and +0.3 dex is not explored and hence is not ruled out. Moreover, that analysis does not yield statistically rigorous results, and it appears that such results may not be produced in color-magnitude analysis of clusters in general. Results in the two cited papers and elsewhere are re-evaluated statistically, with an allowance being made for uncertainty in the cluster reddening. Apparently the best that can be said at present is that the cluster metallicity lies in the range from +0.16 to +0.44 dex. This conclusion is stressed by reviewing the immaturity of the underlying data base. The premature conclusion for a high metallicity turns out to be due largely to neglect of accidental errors, though a tendency to ascribe too much weight to high derived metallicities may also play a role.

Using both high-dispersion and low-resolution data, the metallicities of nine old moving groups and superclusters are analyzed. These stellar groupings include the HR 1614 and Hyades superclusters and the Wolf 630, zeta Her, 61 Cyg, HR 1614, sigma Pup, eta Cep, and Arcturus groups. Samples of these stellar groupings are drawn from Eggen's membership lists. Precautions are taken against problems posed by reddening, visual and spectroscopic binaries, and typographical errors in Eggen's lists. When required, the analyses allow for systematic differences between low-resolution and high-dispersion metallicities. It is found that none of the stellar groupings have the small metallicity dispersion found for a selection of galactic clusters. Instead, the metallicity dispersions turn out to be comparable to the dispersion for a random selection of field stars. For most of the stellar groupings, it does not seem possible at present to learn more by analyzing metallicities. However, one can be more definite about three of them: the HR 1614 supercluster, the HR 1614 group, and the Hyades supercluster. Using a membership list from Eggen (1998c) that is based on Hipparcos astrometry, no evidence is found for the existence of an HR 1614 supercluster. To isolate an HR 1614 group, results from a kinematic analysis (Dehnen 1998) are then used to select a tentative list of members from Eggen's group and supercluster lists. From the mean metallicity of the redefined group, it is found that the group is very unlikely to be a random, magnitude-limited sample of stars. A similar result is obtained for a version of the Hyades supercluster derived from 18 of Eggen's membership lists. About 43% of the stars in this version turn out to be members of the supercluster.

Metallicity calibrations of low-resolution parameters are potentially useful for (at least) two problems: the properties of moving groups, and the supermetallicity problem in K giants. In this paper, metallicity calibrations are derived for six sets of parameters. One of these parameters is the DDO CN index delta CN. This parameter and three others are calibrated for use with evolved G and K stars. Two additional sets of low-resolution parameters are calibrated for use with G and K dwarfs. The calibrations are derived by comparing the input data with two catalogs of homogenized high-dispersion results from diverse authors (see Taylor 1995, 1999a). Using rms errors that are given in the catalogs, intrinsic rms errors are derived for metallicities deduced from the calibrations. The errors turn out to be comparable to those that apply for averaged high-dispersion results.