Explanation of the term e-value

Question

Give a brief explanation of the term e-value.

Answer 1

Anticipate value. The E-value is a parameter which explains the number of hits one can anticipate to see by probability when searching the database of the particular size. It lessens exponentially with the score (or S) that is allocated to a match between two series. Essentially, the E-value explains the random background noise which exists for matches between series. For instance, E-value of one allocated to a hit can be interpreted as meaning which in a database of current size, one may anticipate to see one match with a Same score simply by chance. This means that lower the E-value, or closer it is to the higher is the implication of match. But, it is imperative to note which searches with short sequences can be practically identical and enfold relatively high E-value. This is since the computation of the E-value as well takes in account length of query sequence. This is because shorter sequences enfold a high probability of occurring in database purely by chance.