| |
3.1. Proactive Furniture
39
not turn o after screwing. However, later they realized that they had been trying
to tighten the screws in the wrong direction and corrected their error.
After the experiment, all participants received a paper questionnaire with free-
comment answer fields. First, we wanted to know about common problems oc-
curring in former assembly tasks: 6 participants out of 20 reported that arranging
parts in the proper way had caused problems; 3 complained about unclear instruc-
tions and missing parts. Furthermore, we got single responses about problems with
the order of the assembly sequence, unspecified screwing direction, and problems
with proper orientation of single parts. In addition, we asked, what the participants
opinion is about today’s paper instructions, whether they are comprehensible and
which steps are problematic. The quality of paper instructions supplied with do-it-
yourself (DIY) furniture was rated good by 5, unclear by 5 and problematic by 3
participants. Two subjects noted the additional e ort of reading instructions, an-
other subject admitted to ignore paper instructions because of that fact. Regarding
the LED based instructions, all subjects rated them helpful for the assembly task.
Considering our participants’ relatively high expertise in furniture assembly, this is
a remarkable result. LED’s helped in aligning and joining parts (13 comments), in
identifying parts belonging together (5 comments), and in keeping the right order
of assembly (3 comments). About a third of all participants rated the interactive
screen instructions to be very good, 4 participants judged them to be helpful, 2
viewed them to be similar to the conventional paper instructions. 5 comments men-
tioned the stress of relating between physical parts and the displayed instructions.
The e ectiveness of voice instructions in addition to the LED’s was controversial
among participants: 8 did not see a benefit, 10 were positive and 2 saw little bene-
fit. As an overall result, 70% (14 comments) of all participants preferred the LED
instructions over screen instructions.
3.1.5 Discussion
A system was presented that shows how limitations of today’s instructions could
be overcome. Using the example of a flat-pack wardrobe, the assembly steps were
represented by a formal plan. This plan was used by microprocessors as a knowledge
base to reason about possible further assembly steps from assembly actions detected
through various sensors. LED’s mounted onto furniture parts were used to convey
this information to the user in an integrated way. Finally, a user study evaluated
the e ectiveness of LED instructions. As an overall result it could be shown that
using LED instructions during an assembly process yields a measurable time gain
compared with paper instructions. Beyond that, also errors during assembly can be
reduced using instructions displayed in place. Our results indicate that the presented
LED instructions are perceived as more intuitive, since users do not have to make
the link between the objects on the instructions and the ones in the real world.
|  |
|
| |
|
|
