Privacy-First Approach
StopOdds is a public-interest, non-profit project that helps understand fare inspection patterns on Melbourne public transport. We are committed to transparency and protecting your privacy through technical and procedural safeguards.
What We Collect
We collect only anonymous trip and demographic data:
Required Information:
- Trip count
How many public transport trips you took in the specified period
- Stop count
How many times you were checked during those trips
Optional Demographic Information:
- Age bracket (e.g., 18-24, 25-34)
- Gender identity
- Ethnicity
- Skin tone
- Height bracket
- Visible disability status
- Concession card status
How We Use Your Data
Your anonymous data is used to:
- Calculate stop rates by demographic group
We compute inspection rates per 100 trips for different demographic groups
- Generate statistical models
We use Poisson/Negative Binomial regression to identify patterns
- Provide personal risk estimates
You receive an estimate based on your demographic traits
- Publish aggregate statistics
Public results help inform transport equity discussions
Privacy Protections
K-Anonymity Protection
Any demographic group with fewer than 50 respondents is automatically suppressed from public results. This prevents identification of individuals in small groups.
No Cross-tabulation
We don't publish detailed cross-tabulations that could reveal information about small subgroups, even if individual groups meet the 50-person threshold.
Data Retention
Raw submission data is retained for 12 months for model training and validation. After this period, only aggregated statistics are kept, with no way to trace back to individual submissions.
Security Measures
Data is stored securely with encryption in transit and at rest. Access is strictly limited to automated processing systems. We use industry-standard security practices and regular backups.
Legal Basis & Compliance
This project operates under the Australian Privacy Principles (APP) with specific focus on:
- APP 1: Open and transparent management
This privacy policy and our methodology are publicly available
- APP 2: Anonymity and pseudonymity
All data collection is anonymous with no identifying information
- APP 3: Collection of solicited personal information
We only collect information necessary for our stated statistical purposes
- APP 4: Data quality
We implement validation and quality checks on submitted data
- APP 5: Data security
Appropriate technical and organisational measures protect your data
Your Rights
Since we collect only anonymous data, traditional data subject rights (like access or deletion requests) don't apply in the usual way. However:
- Participation is voluntary
You can choose what information to provide
- No tracking or profiling
We don't build individual profiles or track users across sessions
- Open methodology
Our statistical methods and code are transparent and auditable
Contact & Questions
If you have questions about this privacy policy or our data practices:
- Privacy concerns: privacy@stopodds.com.au
- General questions: info@stopodds.com.au
- Technical issues: Submit on GitHub Issues