Screen guidelines For data entry

Screen Layout for Data Entry Identify screen (name and purpose). Keep number of screens to a minimum. Ensure that all prompts are meaningful and unambiguous. Provide adequate (not voluminous) help on screens and on individual fields. If screen data entry could possibly be rejected on the value of a key field, accept that field as soon as possible and check for validity.

On key field rejection, allow both retry and exit. Allow a quit and save exit. Confirm data before committing. On certain fields (e.g. Date) provide default values. In an on-line situation, where some information is already present, display relevant information. Generate screen or running totals automatically.

Form Filling Dialogues Generally used for transaction entry. Should read left to right, top to bottom. As with manual form filling, the user should be able to skip fields, go back and change field contents or abandon the entry completely. The form contents should not commit the user until they are confirmed. –Where the field can have only one of a limited list of possible values, a pop-up menu may be provided.

Form Filling Dialogues If the input comes from a source document, all validation should be deferred until the end of the entry. If it is from a user or customer, validation should be immediate. Error correction routines should give the completed form to the user and allow changes to the incorrect fields. Prompts should be clearly differentiated from the answer fields.

Form Filling Dialogues Answer fields should be size protected, to prevent users overwriting text. Input items should have the same relative order and format as source data. If multiple screens are required, there should be a logical grouping of data within each screen. Mark all fields for optionality or requirement. Appropriate where a standard sequence of inputs can be predicted.

Screen Formatting Display only relevant information to the user. Display all relevant information to the user. Information should be grouped logically. Upper and lower case lettering should be used. Caption fields (identifying the meaning of individual input and output data fields) should clearly indicate the content of the field and be well differentiated from it.

Screen Formatting Guidelines Leave approximately half the screen blank leave a blank line after every 5th row of a tabular format Leave 4 or 5 spaces between the columns in a columnar format

Screen Template Top 2 or 3 lines should be reserved for title and status information Optional Upper and lower message areas may be provided for user Information on help or instructions –The screen body contains the main information which the screen is seeking to impart. –At the bottom of the screen, 1 or 2 lines show standard facilities (e.g. ESC to exit).

Sample screen for Joe’s Yard

User Interface Design Menus Graphic front ends Dialog Audio Drag-and-drop Intuitive Human Usability Point-and-click Icon List System Event Window String Web browser

Technologies For client-side computing: –HTML forms. –JavaScript. –Proprietary plug-ins (e.g. Flash, etc) –ActiveX controls (Microsoft specific) –Java Applets –Bespoke plug-ins Can be written in C++, Eiffel, Fortran, Cobol, etc. Need a compiler, that will translate your code into a Windows DLL or Unix Shared Library.