Research Methodology
Transparent, rigorous analysis of congressional data from authoritative sources with full methodological disclosure.
Research Approach
Our analysis employs a comprehensive, data-driven approach to examine congressional accountability and electoral competition. We prioritize official government sources, established research institutions, and transparent methodologies to ensure accuracy and reproducibility.
Core Principles
Data Sources
Primary Government Sources
Official election results, candidate filings, campaign finance reports, and expenditure data
Historical election statistics, member biographical data, and voting records
Senate election results, biographical data, and institutional records
Fiscal analysis, budget projections, and economic impact assessments
Research Organizations
Comprehensive election database and candidate information
Campaign finance analysis and lobbying data
Public opinion polling and congressional approval ratings
Political attitudes research and demographic analysis
Key Metrics Definitions
Definition
Percentage of incumbents seeking reelection who successfully win their race
Formula
(Incumbents Reelected ÷ Incumbents Seeking Reelection) × 100
Methodology
Based on general election results; primary defeats count as reelection failures
Notes
Calculated separately for House and Senate; excludes members who retire or seek other office
Definition
Percentage of possible mixed-party election outcomes in presidential election years
Formula
Districts/States with different party control between presidential and congressional races
Methodology
Compares presidential winner by district/state to congressional delegation party control
Notes
Measured only in presidential election years; indicates cross-pressured electorates
Definition
Percentage of Americans who approve of the job Congress is doing
Formula
Monthly polling averages aggregated to annual figures
Methodology
Random sampling of U.S. adults via telephone and online interviews
Notes
Based on Gallup polling with margin of error ±3-4 percentage points
Definition
Ratio of incumbent to challenger average campaign receipts
Formula
Average Incumbent Receipts ÷ Average Challenger Receipts
Methodology
Calculated per election cycle; excludes unopposed races
Notes
Based on FEC reports; includes all receipts through election day
Definition
Number of substantive laws enacted per Congress
Formula
Count of public laws excluding ceremonial and administrative measures
Methodology
Manual review of each law to exclude commemorative resolutions and routine reauthorizations
Notes
Based on Congressional Research Service categorization of 'substantive' legislation
Data Collection Methods
Automated Collection
Where possible, we use automated systems to collect data from official APIs and structured databases. This includes:
- FEC campaign finance data via their REST API
- Congressional voting records from Congress.gov
- Election results from state election offices
Manual Verification
All automated collection is supplemented by manual verification:
- Cross-referencing against multiple sources
- Spot-checking random samples for accuracy
- Reviewing edge cases and anomalies
- Validating calculations against published totals
Historical Data Reconstruction
For historical periods predating digital records, we rely on:
- Official government publications and archives
- Academic datasets with established provenance
- Newspaper archives for election results verification
- Multiple source triangulation for contested figures
Quality Assurance Process
Multi-Stage Validation
- Source Authentication: Verify all data comes from authoritative, official sources
- Cross-Reference Check: Compare data across multiple independent sources when available
- Calculation Review: Independent verification of all mathematical operations and formulas
- Temporal Consistency: Ensure data series are consistent across time periods and methodology changes
- Expert Review: Academic and policy expert review of methodology and findings
- Public Disclosure: Full methodology publication for external scrutiny and replication
Error Detection and Correction
We maintain rigorous error detection protocols:
- Automated range checks for statistical outliers
- Trend analysis to identify potential data breaks
- Regular audits of calculation accuracy
- Public correction process for identified errors
Limitations and Caveats
Data Limitations
- Historical Completeness: Some early data may be incomplete or estimated based on available records
- Definitional Evolution: Some metrics have evolved over time as reporting standards changed
- Sampling Variation: Opinion polling data subject to sampling error and methodological differences
- Reporting Delays: Most recent data may be preliminary pending final official reports
Analytical Limitations
- Correlation vs. Causation: Statistical relationships do not necessarily imply causal relationships
- Predictive Limitations: Historical trends may not predict future outcomes
- Context Dependency: Metrics may be influenced by external factors not captured in the analysis
- Aggregation Effects: National averages may obscure important regional or demographic variations
Scope Limitations
- Federal Focus: Analysis limited to federal elections and institutions
- Quantitative Emphasis: Prioritizes measurable indicators over qualitative assessments
- Institutional Perspective: Focuses on systemic rather than individual-level factors
Updates and Revisions
Update Schedule
Data and analysis are updated on a regular schedule:
- Quarterly: Routine data updates and minor corrections
- Post-Election: Major updates following federal elections
- Annual: Comprehensive methodology review and validation
- Ad-hoc: Corrections for identified errors or significant new data availability
Version Control
All updates are tracked using semantic versioning:
- Major versions: Significant methodology changes or new data series
- Minor versions: Data additions or minor methodology refinements
- Patch versions: Error corrections and clarifications
Change Documentation
All changes are fully documented with:
- Detailed changelog with rationale for modifications
- Impact assessment on existing analyses
- Backward compatibility notes where applicable
- Public notification of significant changes