# Research Methodology Knowledge

## Data Reliability Evaluation

Data quality is determined by source reliability and clarity of documentation.

| Criterion | Judgment |
|-----------|----------|
| Numbers from official statistics (government, municipality) | High reliability |
| Numbers in news articles (with source) | Medium reliability |
| Numbers from personal blogs/SNS (no source) | Low reliability |
| Year/date of numbers is specified | OK |
| Year/date of numbers is unknown | Warning |
| Based on primary sources (official documents, originals) | OK |
| Secondary sources only, primary source unverifiable | Warning |

### Data Source Priority

| Priority | Data Source | Examples |
|----------|------------|---------|
| 1 | Government statistics/white papers | Census, ministry statistics |
| 2 | Municipal open data | City statistical reports, open data portals |
| 3 | Industry groups/research institutions | Think tanks, academic research |
| 4 | News (with primary source reference) | Newspapers, specialized media |
| 5 | News (without primary source) | Secondary reports, aggregation articles |

## Qualitative Analysis Evaluation

Quality of qualitative analysis is evaluated by logical causality and concrete evidence.

| Criterion | Judgment |
|-----------|----------|
| Claims causation with mechanism explanation | OK |
| Claims causation but only correlation exists | Warning |
| Digs into structural factors | OK |
| Stops at surface-level explanation | Insufficient |
| Backed by concrete examples, system names | OK |
| Abstract explanation only | Insufficient |

### Distinguishing Causation from Correlation

"A and B occur together" is correlation. "A causes B" is causation. Claiming causation requires mechanism explanation or elimination of alternative factors.

## Handling Un-researchable Items

Report honestly when items cannot be researched. Do not fill gaps with speculation.

| Situation | Response |
|-----------|----------|
| Data is not public | Report "Unable to research" with reason |
| Data exists but not found | Report "Not found" with locations searched |
| Only partial data available | Report what was found, note gaps |
| Want to supplement with speculation | Clearly mark as speculation with reasoning |