Strohl KLM assignment 4/10/11
Background This KLM analysis is on two GUI versions of the MANTEL interface. These interfaces were produced by Jakob Nielsen at BellCore. The first interface analyzed is known as the Dialog Box interface and the second is known as the Pop-Up Menu interface. A single query and double query task were performed for each of the two interfaces. All tasks assume that there is no system wait time for any of the actions. The telephone numbers in question are already present on the screen. It is assumed that the user begins with one hand on the mouse. The individual performing the KLM has very minimal experience with this task analysis procedure. The individual performing the KLM does not have access to the actual interface. The KLM is based on information of the interface presented on a word document.
Summary The KLM demonstrates that many more steps are necessary for the dialogue box interface compared to the pop-up menu interface. The efficiency differences between the two interfaces become even more apparent when comparing the times on the double query task. The dialogue box interface requires more mental operators. The dialogue box interface also requires the user to alternate hands between mouse and keyboard. When comparing the two interfaces, it is clear that the pop-up menu interface is more efficient for completing the phone number query task. Mental operators were added when performing command functions, except when the terminator functions were redundant (i.e. selecting ok after selecting add). Still, adding mental operators to the time sequence seems difficult to determine without seeing the task being performed by a user. KLM appears to be an efficient method when needing quick information on the length of time expected to complete a task. However, KLM seems limited by its lack of “state of the world� information. A user without experience of this interface would most likely find it difficult to complete the task with the information provided in the KLM.
Key •K: .12 - 1.2 sec; .28 recommended for most users •T(n): n x K sec •P: 1.1 sec •B: .1 sec •BB: .2 sec (Bx2) •BBBB: .4 sec •H: .4 •M: .6 - 1.35 sec; use 1.2 sec •W(t): must be determined •K: Keystroke •T(n): Type a sequence of n characters on a keyboard •P: Point with mouse to a target on a display •B: Press or release mouse button
•BB: Click mouse button •BBBB: Double-click •M: Mental act of routine thinking •W(t): Waiting time for system to respond •H: Home hands to keyboard or mouse
Dialogue Box Interface Single Query Action/operator sequence # of physical operations Mental operator Point to "Databases" on menu bar 1M Left click mouse button 2 Point to "DB3" on drop down menu 1M Left click mouse button 2 Point to "query on telephone" 1M Left click mouse button 2 Point to input field underneath "inquiry on telephone number" 1 Left click mouse button 2 Home hands to keyboard 1 Types telephone number "XXX-XXXX" 8 Home hands to mouse 1 Point to "add" on submenu 1M Left click mouse button 2 Point to "OK" button on submenu 1 Left click mouse button 2
Physical KLM Operator Time P 2.3 BB 0.2 P 2.3 BB 0.2 P 2.3 BB 0.2 P 1.1 BB 0.2 H 0.4 T(8) 2.24 H 0.4 P 2.3 BB 0.2 P 1.1 BB 0.2
KLM total time
15.64
Double Query Action/operator sequence Point to "Databases" on menu bar Left click mouse button Point to "DB3" on drop down menu Left click mouse button Point to "query on telephone"
# of physical operations Mental operator 1M 2 1M 2 1M
KLM Operator P BB P BB P
Time 2.3 0.2 2.3 0.2 2.3
Left click mouse button Point to input field underneath "inquiry on telephone number" Left click mouse button Home hands to keyboard Type 1st telephone number "XXX-XXXX" Home hands to mouse Point to "add" on submenu Left click mouse button Point to right of telephone number entered into input field Left press mouse button Point to left of telephone number entered into input field Release mouse button Home hands to keyboard Type 2nd telephone number "XXX-XXXX" Home hands to mouse Point to "add" on submenu Left click mouse button Point to "OK" button on submenu Left click mouse button Total time
2 1 2 1 8 1 1M 2 1 1 1 1 1 8 1 1M 2 1 2
BB P BB H T(8) H P BB P B P B H T(8) H P BB P BB
0.2 1.1 0.2 0.4 2.24 0.4 2.3 0.2 1.1 0.1 1.1 0.1 0.4 2.24 0.4 2.3 0.2 1.1 0.2 23.58
Pop-Up Menu Interface Single Query Action/operator sequence Point to telephone number on screen Left press mouse button Point to database Release mouse button
# of physical operations Mental operator 1M 1 1M 1
KLM Operator P B P B
Time 2.3 0.1 2.3 0.1
Total time
4.8
Double Query Action/operator sequence Point to telephone number on screen Left press mouse button Point to database Release mouse button Point to 2nd telephone number to query on screen Left press mouse button Point to database Release mouse button Total time
# of physical operations Mental operator 1M 1 1M 1 1M 1 1M 1
KLM Operator P B P B P B P B
Time 2.3 0.1 2.3 0.1 2.3 0.1 2.3 0.1 9.6