HCI Assignment 4 §

A §

A.1 §

B §

B.1 §

The KLM Model decomposes the task into operators, which are then summed up to calculate an estimate amount of time it will take to complete the task. Since it uses estimated values for the operator times it assumes the user is an average one → average skill and amount of errors. If someone is very skilled, the KLM model will underestimate that person (or over estimate unskilled users).

B.2 §

1. H: Homing (moving hand between mouse/keyboard) 0.4s
2. P: Pointing (Pointing with a mouse to a target), calculated with Fitts’ law
3. BB: Clicking the mouse button, $2\ast 0.1s$

B.3 §

B.3.1 §

First Draft §

Tab: Next field Enter: Next field Fields get checked for correct value on submit

Second Draft §

Tab: Next field Enter: Next Field Fields get checked for correct value on submit

Third Draft §

Tab: Next field Enter: Submit form Fields get checked for correct value on submit. Pick date in calendar widget, slide color slider to change color.

B.3.2 §

Task: Fill out the form and submit it

First UI: §

• Enter name: 15K, B(tab)
• Enter email: 15K, B(tab)
• Enter birthday: 8K, B(tab)
• Enter color name: 6K, B(tab)
• Enter height: 3k, B(Tab)
• Enter weight: 2K, B(Tab)
• Enter shoe size: 2k
• Click submit: H, P, BB

= 16.58

Second UI: §

• Enter name: 15K, B(tab)
• Enter email: 13K, B(tab)
• Enter birthday: 8K, B(tab)
• Enter color: H, P, BB,
• Navigate cursor to next field: P, BB
• Enter height: 5k, B(Tab)
• Enter weight: 4K, B(Tab)
• Enter shoe size: 2k
• Click submit: H, P, BB

= 17.24s

Third UI: §

• Enter name: 15K, B(tab)
• Enter email: 13K, B(tab)
• Enter height: 3k, B(Tab)
• Enter weight: 2K, B(Tab)
• Enter shoe size: 2k
• Enter birthday: H, P, BB, BB, BB
• Enter color: P, D(1,1)
• Navigate cursor to next field: P, BB
• Click submit: H, B(Enter)

= 16.16

Conclusion §

I was personally surprised that the last UI was the fastest (1.08s faster than the slowest), because it seemed less efficient than the first one although it looks better. Certain types of inputs just take a lot of time to complete (e.g. birthdate), which is why widgets can improve the time to complete. Shortcuts such as TAB to go to the next field as well as enter to complete a form are also big time savers. The H operator always takes up a lot of time, which is why it should be avoided if possible.

C §

C.1 §

Gulf of evaluation §

= the steps a user has to perform in order to work out a goal they want to pursue. This reaches from perceiving a state to interpreting and evaluating it.

Gulf of execution §

= the steps a user has to perform in order to reach a goal, this reaches from forming an intend to act to executing the necessary actions.

C.2 §

graph TD 
	subgraph execution ["Gulf of execution"]
	e1["intend to act"] --> e2["plan actions"]
	e2["plan actions"] --> e3["execute actions"]
	end

	subgraph evaluation ["Gulf of evaluation"]
	ev1["perceiving the state"] --> ev2["interpreting perception"]
	ev2["interpreting perception"] --> ev3["evaluating interpretation"]
	end	
	
	goal --> e1
	ev3 --> goal

Examples §

• Perceived state: My computer is not playing my music
• Interpreting perception: The sound is actually just very low, which is why you couldn’t hear it
• Evaluating interpretation: The computer can actually play sound, but it is very low at the moment
• Goal: I need to increase the volume in order to listen to my music
• Intend to act: The goal becomes the intend to act
• plan actions: I need to move my hand to the volume knob and twist it so it increases the volume, if that doesn’t work i need to adjust the system settings
• execute actions: execution of planned actions