Mayhew's Book (chapt. 5)

Designing Fill-In Forms

1. Organization and Layout

• Design and organize the form to support the task

• Organize groups of items related semantically by:
  • sequence of use,
  • frequency of use, and/or
  • relative importance.

• Keep the number of groups to a minimum, while limiting the size of groups to 12-14 chars wide and 6-7 lines high (within 5 degree visual angle).

• Use white space to:
  • create balance and symmetry,
  • lead the eye in the appropriate direction.

• Separate logical groups by spaces, lines, color, or other visual cues.

• Screens:
  • High-frequency users + slow system RT --> Minimize the number of screens.
  • Low-frequency users + fast system RT --> Maximize screen clarity.

• Keep related and interdependent items on the same screen.

2. Caption and Field Design

• In western cultures:
  • for single fields, place caption to left.
  • for list fields, place caption above.
    • left justified above alpha lists.
    • right justified above numeric lists.

• Justify captions and fields according to user, task, and data type.

• Separate the (longest) caption (in a left-justified group) from its field by no more than 1-2 spaces (following the delimiter, for example, a colon). Separate one caption field group from another by three or more spaces horizontally, or by one or more lines vertically.

• Break up columnar fields or long columns of single field items into groups of 5 separated by a blank line.

• Provide distinctive field group and section headings in complex forms.

• Distinguish fields (i.e., contents) from captions (i.e., labels).

• Captions should be brief, familiar and descriptive.

• Indicate the number of character spaces available in a field.

• Indicate when fields are optional.

3. Input Formats

• Consider providing system completion of unambiguous partial input.

• Consider providing pop-up or pull-down menus for fill-in forms with many but well-defined entry options.

• Avoid complex rules for entering data in the various fields of a form.

• Provide meaningful (in field) groupings to break up long input formats (chunking).

• Provide defaults whenever possible. Allow simple (single key) acceptance of defaults.

  3.1. Designing input data

• Make high-frequency inputs easy to express (e.g., y/n)

• Let the user specify the unit of measurement. Do not require transformations or calculations.

• Design meaningful input data whenever possible.

• Allow abbreviated input when it can be unambiguously interpreted (e.g., "y" for "yes")

• A system should be "case blind" when it really does not matter (e.g., "yes", "Yes" or "YES")

• Keep input fields short if possible.

• Do not combine letters and numbers in a single field.

• Avoid frequent shifts between upper- and lower-case characters.

• Avoid uncommon letter sequences.

• Do not require leading zeros.

4. Prompts and Instructions

• Provide prompts when use will be relatively infrequent, inputs must be formatted, and users are not working from a source document.
  • i.e., help user with syntax
  • e.g., (Last, First Middle)

• Prompts should be brief and unambiguous.

• Place prompts to the right of fields, or in a MicroHelp line at the bottom of the screen/window.

• Provide instructions for navigation and completion on the screen or through on-line help.

• Place instructions in a consistent location across screens and make them visually distinctive.

• Use consistent terminology and consistent grammatical form and style in instructions.

5. Navigation

• When a form is first entered, position the cursor in the most likely default position.

• Arrange field groups consistently with default cursor movement. Vertical groups are preferable to horizontal if cursor movement can be vertical.

• Allow forward and backward movement by field and within fields.

• Make protected areas on the screen completely inaccessible. Allow the cursor to rest only on user-editable areas.

• Do not use auto tab unless fields have fixed lengths and users are high frequency and experienced.

• Provide titles and page numbers or place markers on screens in a multiscreen form.

• Direct manipulation increases flexibility, speed, and ease of learning for navigation through fields.

6. Error Handling

• Allow character edits in fields.

• Place the cursor in the error field after error detection. Highlight the error field if possible.

• For independent fields, withhold error reporting until user request.

• Provide semantic and syntactic information in error msgs depending on user knowledge.