Curiosity and support
Mascot reactions and optional progressive hints create a reason to inspect again.
CEDIS | Universidade de Brasília
DevDog
A gamified web platform for teaching code smell identification
CEDISThe challenge is not memorizing smell names. It is making a defensible judgment in unfamiliar code.
CEDISDevDog keeps the learner in the decision loop
Guia
Theory consultation with concepts and examples before or between attempts.
- just-in-time study
- short explanations
- examples aligned with practice
Farejador
Contextualized challenges in which the learner selects lines and classifies smells.
- manual localization
- 19 smell categories
- immediate feedback
CEDIS
Guia and Farejador in the implemented system
The tool connects theory consultation with deliberate practice. The system does not reveal the answer before the learner decides.
- inspect code
- select suspicious lines
- classify the smell
- receive oracle-based feedback
CEDISGamification is not decoration. Each reward and hint must reinforce the inspection task.
CEDISFrom motivational drivers to concrete mechanics
Ownership and strategy
Learners earn petiscos and decide when to spend them on hints.
Progress and competence
Scores, stars, attempts, best score and immediate feedback make progress visible.
Low-pressure relatedness
Comparison is scoped to each exercise, avoiding a dominant global leaderboard.
CEDISThe gamified learning loop
1
Inspect
Read context and code.
2
Decide
Select lines and smell type.
3
Feedback
Receive line-level oracle feedback.
4
Earn
Gain score, stars and petiscos.
5
Spend
Unlock progressive hints.
6
Retry
Perform an informed second inspection.
CEDISThe judgment is the game action
DevDog keeps the learner responsible for the central task: identifying where the design symptom appears and what kind of smell it represents.
- manual line selection
- smell-type discrimination
- penalty for indiscriminate selection
- retry supported by hints
CEDIS
Feedback closes the loop
After a submission, DevDog returns performance feedback, mascot reaction, score, stars, petiscos and the possibility of another attempt.
- feedback is immediate
- hints are progressive
- petiscos become a strategic resource
- the retry is informed practice
CEDISA lightweight, reproducible web implementation
React/Vite
Pages, code viewer, hints, result dialog and mascot states.
Express API
Authentication, attempts, hints, recommendation and statistics.
Prisma + PostgreSQL
Persistent users, exercises, smell lines and attempts.
Docker Compose
Reproducible orchestration of database, migrations, API and web client.
CEDISWhat we learned—and what we do not claim
Supported by current evidence
- the workflow can be followed in a prototype
- feedback informed interface refinements
- game mechanics are implemented, traceable and deployed
Not yet demonstrated
- learning gains
- long-term retention or transfer
- causal effects of individual mechanics
CEDISReady to sniff out code smells?
Live system: https://devdog.cedis.tec.br · Source code: https://github.com/CedisUnB/CodeSmellGamification · Demo: https://zenodo.org/records/20298757
CEDISReferências
- Silva Júnior, L. R.; Freitas, S. A. A.; Lanna, A. L. P. M. DevDog: A Gamified Web Platform for Teaching Code Smell Identification. SBES 2026 Tools Track.
- Fowler, M. Refactoring: Improving the Design of Existing Code. 2nd ed. Addison-Wesley, 2018.
- Deterding, S.; Dixon, D.; Khaled, R.; Nacke, L. From game design elements to gamefulness: defining gamification. MindTrek, 2011.
- Ryan, R. M.; Deci, E. L. Self-determination theory and the facilitation of intrinsic motivation, social development, and well-being. American Psychologist, 2000.
- DevDog live system: https://devdog.cedis.tec.br.
- DevDog source code: https://github.com/CedisUnB/CodeSmellGamification.