Menu Interfaces

Benefits of menu’s:Learnability, memorability, error avoidanceMinimize memory load

Drawbacks: possible inefficiencyhierarchical complexity (menu trees)

Menu Interfaces – Design Issues and Choices

What kind of menu?1-level v. hierarchical v. “linear”

Affordance of menu: how to activate/deactivatepull down, pop-up, dropdown list

always present: list, toolbar, toolbox, radio buttonsappears automatically

1-level Pull-down Menu

2-level Hierarchical Menu

Select Database

1. Employee database

2. Customer database

3. Product database

4. Sales database

>> 1Type number of desired selection and <Enter>

Old-style linear menu system

Select Function

1. Add a records

2. Delete records

3. Print report

>> 3Type number of desired selection and <Enter>

Select Report Style

1. Print selected records

2. Print statistics

3. Print selected records and statistics

>> Type number of desired selection and <Enter>

Menu Design Issues and Choices (cont.)

Number of items items per menu = “breadth”

Number of active choices

Menu title names

Menu item names

Menu item ordering

Menu Design Issues and Choices (cont.)

Appearancetext v. iconic items v. bothhorizontal v. vertical v “fast and vast”

Idioms:selection list check boxmenu bar radio buttonsdrop-down selection list toolbarspush buttons/hyperlinkspie menus

Q. Are embedded links menu’s ??

A. Only if they are arranged in a listlist

Menu Design Issues and Choices(cont.)

Item Selection mechanism (affordance) by:Mouse clickDrag and release (Macintosh)Keyboard entry

- arrow cursors & <RET>- Mnemonic letters & <RET>- Other “shortcuts”

Affordance for Hierarchical Menu selection:MouseDownMouse-over with pop-up levels (use of DELAYS)

Efficiency of Menu’s

Response Time and Display Rate

The speed at which a user can move through menus may determine their attractiveness as an interface mechanism. User performance and preference favors broader, shallower menus

Efficiency of Menu’s (cont.)

Menu shortcuts:Alt-key opens menuCTL or function key activates menu item

Menus with typeahead recommended when: Menus are familiar Response time/display rates are slow BLT approach: single-letter menus with typeahead leads to concatenation of

hierarchical menu selections into mnemonics.

Menu names or bookmarks/macros for direct access

Hierarchical MenusDesign Issues

Taxonomy design problem Male, female Animal, vegetable, mineral Fonts, size, style, spacing

Depth versus Breadth - difficult trade-off

Depth v. Breadth Trade-off in Menu Design

Kiger (1984) grouped 64 menu items 6 ways:8, 8 | 4, 4, 4 | 2, 2, 2, 2, 2, 2 | 4, 16 | 16, 4

22 subjects performed 16 searches.Rated for speed, accuracy, preference.2 X 6 was worst in all categories, 8 X 8 rated highly

Models of Menu Performance

Time for one selection:

T = k + c * log2b (b is breadth; k,c parameters representing scan and selection time)

Total time = D * T where D is depth of tree = log b N

Hierarchical Menus

Models of Menu Performance (cont.)

Experiment with 4096 items: 16 per menu twice as fast as 2 per menu

Hierarchical Menus

Example 1: N = 4096, b = 16, D = 3

Predicted time for a search is 3 * (k + c * 4) or [3k + 12c]

Example 2: N = 4096, b = 4, D = 6

Predicted time for a search is 6 * (k + c * 2) or [6k + 12c]

c is time to visually search, k is mechanical overhead ofmoving the mouse, clicking, etc.

Menu Design Guidelines

Task-related GroupingCreate groups of logically similar items

Form groups that cover all possibilities Make sure that items are non-overlapping Use familiar terminology, but ensure that items are distinct

from one another

Menu Design Guidelines (cont.)Ordering Menu Items

The order of items in the menu is important, and should take natural sequence into account when possible: Time Numeric ordering Physical properties

When cases have no task-related orderings, the designer must choose from such possibilities as: Alphabetic sequence of terms Grouping of related items Most frequently used items first Most important items firstUse horizontal bars to create within-menu grouping

Menu Design Guidelines (cont.)Naming of Menu Items

Titles - For single menus, use a simple descriptive title.

For linear menus, use the exact same words in the higher-level menu items as in the titles for the next lower-levelmenu. E.g. if a menu item is called Business and Financial Services, the next screen should have that phrase as its title.

Phrasing of menu items Use familiar and consistent terminology Ensure that items are distinct from one another Use consistent and concise phrasing Bring the keyword to the left

Menu Interfaces - Summary of Design Issues

Choose type of menus (simple, linear, tree structured)Choose menu selection mechanism ( & shortcuts)Grouping/organizing menu items

Taxonomy design for tree-structured menusDepth v. breadth trade-off

Select names of menu choicesOrder choices within each menuSelect menu titles