differences between our BALQSO and nonBALQSO samples in two ways: first by comparing the ensemble averages in the form of composite spectra and second in terms of the spectral indices and reddening values that result from our fits of each individual quasar to a template. Emission and absorption properties of BALQSOs will be discussed in § \[sec:emline\].

Composite Spectra Measurements\[sec:compred\]
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To compare the composite spectra continua, the EDR composite spectrum is fitted to each of the BALQSO composite spectra by the $\chi^2$-minimization procedure described in § 3 of (2003). In short, the spectra are compared in wavelength regions where emission and absorption are typically absent. The algorithm iteratively searches for values of the spectral index and reddening that provides the best fit. The resulting $\alpha_P$, \[$\alpha_{RP},E(B-V)_{RP}$\], and $E(B-V)_{R}$ values are given in Table 1. The single-parameter fits yield consistent results that suggest increased reddening with increasing BAL strength. The two-parameter fits are more difficult to interpret, especially given the strong degeneracy between spectral index and reddening when performing a two-parameter fit; see Figure 3 in (2003).

As a simplistic check on our method and code, we fit the EDR quasar composite spectrum to itself and indeed found that the 