Input questions provide the user with a form field into which the user can type letters or numbers, depending on the specific question type and data constraints.
Example: Often used to allow "Other, Specify" options in questions which otherwise have only a limited selection of answers.
In KoBo Collect, a text input question is presented to the user like this.
The keyboard will pop up when a text input question is loaded, the entry box will allow any kind of text, including numbers.
Entry data is stored as a string of unlimited length, though transferring this data to a database may have its own limitations, as many types of database fields have size limitations. Generally, text input should be used for recording short, qualitative answers.
Wherever possible, it is better to try and predict the possible answers to a question and present those answers to the user as options in a single-select or multi-select question.
Use text input to allow users to give "Other, Specify" answers at the end of a group of select options.
Example: Used to input "Age of respondent", user can only enter whole numbers. If age is <18, data constraints are not met and a custom error message is presented to the user stating "Only adult respondents are allowed."
In KoBo Collect, an integer or decimal input question is presented to the user like this.
Note the italicized hint "try entering a number > 10", the form designer has placed a constraint on the numerical data entry that will generate an error message if the number entered is greater than 10. The user can only enter whole numbers that are less than 10.