A method for nucleic acid sequencing includes: (a) disposing a plurality of template polynucleotide strands in a plurality of defined spaces disposed on a sensor array, at least some of the template polynucleotide strands having a sequencing primer and a polymerase operably bound therewith; (b) exposing the template polynucleotide strands with the sequencing primer and a polymerase operably bound therewith to a series of flows of nucleotide species flowed according to a predetermined ordering; (c) determining sequence information for a plurality of the template polynucleotide strands in the defined spaces based on the flows of nucleotide species to generate a plurality of sequencing reads corresponding to the template polynucleotide strands; and (d) aligning the plurality of sequencing reads using an alignment process comprising a first set of alignment criteria or penalties that are based on biological changes in sequence and a second set of alignment criteria or penalties that are based on a sequencing error mode.