The window allows to select how missing values are handled.

Empty values or values that start with a ? are treated as missing values. There are two ways to exclude (some) missing values from the analysis:

• Exclude Samples with more than 3%, 5%, or 10% missing values in the distance columns
• Exclude columns that contain any missing values from distance calculation

If missing values still occur, they can be treated in two different ways:

• missing values are an own category: When comparing two missing values, they are equal. When comparing a non-missing value with a missing value, they are different.
• pairwise ignore missing values: When comparing two missing values, they are equal. When comparing a non-missing value with a missing value, they are equal.

Missing value categories

Three different categories of missing values can appear in SeqSphere+:

• ? (not found): No target sequences were found in the scanning process
• ? (failed): Target QC procedure checks failed (see Target Parameters).
• ? (new): New allele found that have similar (according to the defined parameters) but no identical matches in the allele library. It may be possible to submit the alleles and assign new allele types.