Fuzzy search for keywords in free text
Free text entered by users might have typos. How to find approximate, misspelt matches to the searched string?
Advantages and drawbacks of free text
Some people at work fill text fields in some forms. Later their colleagues analyse or process the free text in thousands of forms and draw some meaningful conclusions. For example, imagine doctors who fill patients records and also do clinical research using the data collected inside their hospital.
Compared to complicated and inflexible forms with lots of controls with lots of predefined options, the important advantage of the forms made up mostly of text fields is that text fields allow entering any information quickly. And later when it is really needed, with some additional effort the text can be transformed into more structured data.
When we type we inevitably make typos. The more users are in a rush, the more mistakes they make. Spell checkers help to correct grammar errors, but not the errors in the words outside the language dictionary, for example fancy product names or scientific terms.