Enhancing online forms: Use format specifications for fields with format restrictions to help respondents

Field format restrictions are often used in online forms to impose certain formatting and content rules on users, such as minimum password length or date entry format. In this study, the question whether and how format restrictions for fields in online forms should be communicated to Internet users was explored. In an online study with n = 166 participants, four ways to communicate format restrictions were investigated: (1) no visual format restriction, (2) format examples, (3) format specifications, and (4) both format restrictions (examples and specifications). Results show that providing details of any format restriction to users in advance leads to significantly fewer errors and trials. The most efficient way to communicate field format restrictions to users is by stating the imposed rule (format specification). Providing an additional example neither helps nor constrains users.

This figure shows how the error rate in web forms decreases if format restrictions (e.g. minimum length of a password, correct formatting of a date), providing textual details of these format restrictions to users are used.Figure optionsDownload as PowerPoint slideResearch highlights
► If a field in a web form is implemented using format restrictions (e.g. minimum length of a password, correct formatting of a date), providing textual details of these format restrictions to users in advance leads to significantly fewer errors and trials.
► This study shows, that the most efficient way to communicate these field format restrictions to users is by stating the imposed rule to explain the correct formatting (e.g. “Date of birth in dd-mm-yyyy format”).
► Providing an additional example (e.g. “23-04-1975”) neither helps nor constrains users.
► This study also shows, that the difficulty of entering correct answers does not only depend on the information provided via format restriction labels, but also on the implied data restriction.
► Website developers should consider very carefully if a restriction is really necessary. Even with the best methods to communicate format restrictions users made mistakes. These errors slow users down and may even lead to higher dropout rates.