0
2.5
5
7.5
10
12.5
15
17.5
20
22.5
25
0 25 50 75 100 125 150 175 200 225 250
Number of Triples
Number of Game Sessions
w=100 collected
w=100 verified
w=100 deleted
w=10 collected
w=10 verified
w=10 deleted
w=1 collected
w=1 verified
w=1 deleted
Figure 7: Collected and verified triples (2nd experiment).
weight1
weight10
weight100
0 200 400 600 800 1000 1200
Number of Quizzes Sent
fib_obj(ANSWER)
fib_obj(SKIP)
fib_sub_obj(ANSWER)
fib_sub_obj(SKIP)
fib_pred_obj(ANSWER)
fib_pred_obj(SKIP)
fib_tfquiz(TRUE)
fib_tfquiz(FALSE)
Figure 8: Breakdown of users’ answers (2nd experiment).
4.2.2 Simulation Results and Discussion
As shown in Figure 7 and 8, the results of the experi-
ment with 20 virtual users show that out of 25 triples,
all 10 triples that 80% and 100% of the users have in
common were moved into the formal knowledge base.
By contrast, all 5 triples that only 20% of users had
were considered false and removed from the tempo-
rary knowledge base, while the other triples remained
in the temporary knowledge base. Note that users’ re-
sponses of FALSE for true-or-false quizzes were ob-
served for all the cases (Figure 8). In this way, only
the triples possessed by more users than the threshold
α were verified, and triples possessed by fewer users
than the threshold β were eventually removed from
the temporary knowledge base.
We also found that the system effectively inter-
leaved the collection and verification of knowledge
even when multiple object items existed for a pair of
subject and predicate.
5 CONCLUSION
In this paper, we presented an approach to perform in-
terleaved collection and verification of triples to build
a knowledge graph using crowdsourcing. In this ap-
proach, quizzes were introduced to collect and verify
triples that constitute a knowledge graph: fill-in-the-
blank quizzes for knowledge collection and a true-or-
false quiz for knowledge verification.
Score functions based on the user’s history were
adopted to improve knowledge graph building effi-
ciency. To interleave the collection and verification
processes, we also introduced a weight in score func-
tion calculations. The simulation results show how
weight can influence the performance of the collec-
tion and verification of knowledge. In addition, the
verification threshold works reasonably when a ma-
jority rule is adopted.
Since currently only triples collected in the knowl-
edge collecting quizzes are considered for the verifi-
cation task, we plan to incorporate triples collected
from a variety of other sources into the target of
the verification task in future work. Furthermore, it
would be beneficial to expand the gamification ele-
ments to motivate users. We plan to examine how
different ways of giving rewards to users affect the
collection and verification of triples. For example, we
are considering offering multiple tasks with different
rewards to the user and letting the user choose one of
them for task execution.
ACKNOWLEDGEMENTS
This work was partially supported by JSPS
KAKENHI Grant Number 18K11451.
REFERENCES
Bu, H. and Kuwabara, K. (2021a). Task selection based
on worker performance prediction in gamified crowd-
sourcing. In Jezic, G., Chen-Burger, J., Kusek, M.,
Sperka, R., Howlett, R. J., and Jain, L. C., editors,
Agents and Multi-Agent Systems: Technologies and
Applications 2021, pages 65–75, Singapore. Springer
Singapore.
Bu, H. and Kuwabara, K. (2021b). Validating knowledge
contents with blockchain-assisted gamified crowd-
sourcing. Vietnam Journal of Computer Science,
pages 1–21.
Cao, M., Zhang, J., Xu, S., and Ying, Z. (2021). Knowledge
graphs meet crowdsourcing: A brief survey. In Qi,
L., Khosravi, M. R., Xu, X., Zhang, Y., and Menon,
V. G., editors, Cloud Computing, pages 3–17, Cham.
Springer International Publishing.
Hogan, A., Blomqvist, E., Cochez, M., D’amato, C., Melo,
G. D., Gutierrez, C., Kirrane, S., Gayo, J. E. L., Nav-
igli, R., Neumaier, S., Ngomo, A.-C. N., Polleres, A.,
Rashid, S. M., Rula, A., Schmelzeisen, L., Sequeda,
Toward Crowdsourced Knowledge Graph Construction: Interleaving Collection and Verification of Triples
381