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For an oligonucleotide frequency matrix F_L-m+1,k={f_ij} of the length L and an arbitrary DNA sequence S=s₁...s_i...s_L of the same length L, the simplest recognition Score is calculated:

Formula (2) calculates the Score_# value, the scale range of which is increasing with the growth of the site length L, and decreasing with the growth of the size k of the oligonucleotide alphabet {E₁, ..., E_j, ..., E_k}. According to Zadeh's fuzzy sets (Zadeh, 1965), the Score values calculated by the formula (2) were transformed into the normalized partial recognition scale:

where the partial recognition’s rule is as follows:

Formula (3) gives the normalized Score₀(S), the mean value of which averaged over all the known sequences of the site under study equals to “1”, whereas the mean value averaged over the random DNA sequences equals to “–1”. This Score₀ scale is common for all the oligonucleotide frequency matrices compiled by the MATRIX database for any functional DNA site expressed within any alphabet.