Question 1
(24 marks)
A human-computer interaction (HCI) researcher was interested in examining
whether humans are better able to use a joystick or a mouse to point a computer cursor.
She therefore constructed an experiment in which participants used either a joystick
(joystick condition) or a mouse (mouse condition) to point a cursor to a target displayed on
a computer monitor. She measured the time (seconds) that it took to place the cursor over
the target (dependent variable referred to as time, where a higher time score indicates
poorer performance). To determine whether potential benefits of using the joystick or
mouse generalized to difficult HCI scenarios, the target was either stationary (static
condition) or moved slowly across the computer screen at a constant velocity (motion
condition). Participants were randomly and uniquely assigned to 1 of 4 conditions in the
interface (levels: joystick, mouse) × target type (levels: static, motion) experimental design.
Given the data collected by the researcher (see Table 1 below), what can she conclude
about how easily humans interact these HCI interfaces and how are these HCI interfaces
influenced by target type? Include a line graph of the means.
3
Table 1. Target localization times in the interface × target type conditions.
Subject Interface Target Time
1 Joystick Static 2.53
2 Joystick Static 2.24
3 Joystick Static 3.16
4 Joystick Static 1.50
5 Joystick Static 3.06
6 Joystick Static 2.76
7 Joystick Static 2.57
8 Joystick Static 4.03
9 Joystick Static 1.70
10 Joystick Static 0.70
11 Joystick Motion 2.00
12 Joystick Motion 2.54
13 Joystick Motion 2.23
14 Joystick Motion 0.10
15 Joystick Motion 0.75
16 Joystick Motion 1.30
17 Joystick Motion 2.11
18 Joystick Motion 2.60
19 Joystick Motion 1.05
20 Joystick Motion 2.05
21 Mouse Static 1.39
22 Mouse Static 0.67
23 Mouse Static 1.62
24 Mouse Static 1.69
25 Mouse Static 0.29
26 Mouse Static 2.29
27 Mouse Static 0.93
28 Mouse Static 1.32
29 Mouse Static 0.33
30 Mouse Static 1.67
31 Mouse Motion 1.35
32 Mouse Motion 1.29
33 Mouse Motion 1.31
34 Mouse Motion 2.48
35 Mouse Motion 1.83
36 Mouse Motion 1.03
37 Mouse Motion 2.18
38 Mouse Motion 2.01
39 Mouse Motion 1.79
40 Mouse Motion 1.87
Sample Solution
