the ratio (4) can be transformed into a score taking values between 0 and 1, where 𝛽 is a userdefined parameter. We refer to the index 𝐼 * + " as a logicality index as a value of 1 indicates that the spectrum contains no illogical neutral losses. The second method we present is the Simple Search Hitlist Method (SS-HM). Pseudocode for this method is included as Algorithm 2 in Appendix A. The SS-HM seeks to improve predictions generated using the PIM of a query by considering how the PIM performs for similar mass spectra as identified through a mass spectral library search-it can be thought of as a predictor-corrector method, motivated by ideas presented by Scott and Scott et. al. The evaluation of proposed mass corrections is built on the principles of chemical substructure identification by library searching presented by Stein. The SS-HM requires a query spectrum and reference spectral library, and its prediction is 𝑚 " , . The algorithm begins with a Simple Similarity Search of the query spectrum. For the top 𝑛 -entries of the hitlist, the difference between their true nominal molecular mass and predictions obtained using the PIM are computed; here we refer to these differences as mass corrections. The collection of 𝑛 unique mass corrections computed form a set of potential mass corrections, we call 𝑐, for the PIM prediction of the analyte. Each element of the set 𝑐 is then assigned an index, 𝜉 . # , based on its associated simple match factors versus those associated with all potential mass corrections,