Blog of Andrés Aravena
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# 6. Word Size

09 November 2022

For a fast search we use a large word size, which may miss some results. To find more results, i.e. to be more sensitive, we use a small word size.

## Student 1 100

The Word size should be smaller if we want to get a result of sensitive search. Bu if we want to get a faster search, we can increase the Word size. The exact definition of the word size is the length of the seed that initiates an alignment. Since BLAST initiates the extension once it finds the matches between the query and subject, smaller word size will give us more sensitive search.

## Student 2 0

For faster search we can choose word size “2”. It reads sequences two by two and gives the similar or same sequence pieces. But it is not that sensitive. For sensitive search we can choose word size “6”. It reads sequences six by six and again gives the similar or same sequence pieces. It’s not fast as the word size 2 but it’s much more sensitive.

## Student 3 50

When word size increase, sensitivity decreases.

## Student 4 99

Words of larger size are faster to search. But they may miss subjects with many mismatch.

Small word size is more sensitive. But it will take longer time to find them all.

## Student 5 99

When we want to seach faster something in BLAST, we should use longer lenght and specific sequences, however if we want to sensitive seach, we should use shorter sequences.

## Student 6 100

For faster search i use bigger word size. For sensitive search i use smaller word size.

## Student 7 100

I use words of larger size for faster search. But they may miss subjects with many mismatches. I use small word sizes for more sensitive searches but it will take longer to find them all.

## Student 8 99

for faster search long word size is used. Because it is a big part query and it will be search that big part query inside other subjects. And the possibility of finding all letter in the query will be less so it will be faster to search. for a sensitive search, we use short word size. because we can find short word size in many subjects the possibility is high and the time will be longer.

## Student 9 100

Words of larger size are faster to search but subjects with many mismatches might be missed. Small word size is more sensitive, however, it will require a longer search time.

## Student 10 0

Word size is used on BLAST to determine our compare parts also small word size is faster than big word size. However for sensitive search big word size is used.

## Student 11 50

The bigger the word size, the faster the search. For example, in the Protein BLAST, the maximum word size is 6. If I proceed with my work on Protein BLAST, I will choose the word size “6” to get a faster search.

## Student 12 0

If we want to do a fast search in blast, our word size must be small. However, if we want to do a sensitive search, word size must be larger.

## Student 13 100

For a faster search I use bigger word size like 6 because speed increase with word size. And for sensitive search I use smaller word size like 2 because sensitivity decrease with word size.

## Student 14 100

I will use bigger words size for a faster search because there will be less segments, but smaller words for a sensitive search.