Data Research Protocol

Principle: DATA FIRST, CODE SECOND.

Workflow

1. LOAD -- Load data, verify accessibility
2. SCHEMA -- Show structure (types, shape, samples)
3. PROFILE -- Find risks (nulls, duplicates, anomalies)
4. HYPOTHESIS -- What do we want to prove?
5. EXPERIMENT -- One small test
6. DOCUMENT -- Record findings per 5W+H format

Schema Analysis (MANDATORY before any conclusions)

Choose analysis method based on project stack:

PostgreSQL / SQL (for database analysis)

-- Schema inspection
SELECT column_name, data_type, is_nullable
FROM information_schema.columns WHERE table_name = 'target';

-- Data profiling
SELECT count(*), count(DISTINCT column_name),
       count(*) FILTER (WHERE column_name IS NULL) as nulls
FROM target;

-- Distribution
SELECT column_name, count(*) FROM target GROUP BY 1 ORDER BY 2 DESC LIMIT 20;

TypeScript (for API/application data)

// Shape and types
console.log(`Records: ${data.length}`);
console.log(`Keys: ${Object.keys(data[0] || {})}`);

// Profiling
const nullCount = data.filter(item => item.field == null).length;
const uniqueCount = new Set(data.map(item => item.field)).size;
const duplicates = data.length - uniqueCount;

Python / pandas (for file-based data)

print(f"Shape: {df.shape}")
print(f"dtypes:\n{df.dtypes}")
print(f"head:\n{df.head()}")
print(f"nunique:\n{df.nunique()}")
print(f"nulls:\n{df.isnull().sum()}")

Risk Profiling

Risk	SQL Check	TypeScript Check	Python Check
Missing data	count(*) FILTER (WHERE col IS NULL)	data.filter(x => x.col == null).length	df.isnull().sum()
Duplicates	count(*) - count(DISTINCT col)	data.length - new Set(data.map(x => x.col)).size	df.duplicated().sum()
Wrong types	SELECT pg_typeof(col)	typeof item.field	df.dtypes
Outliers	percentile_cont(0.99)	Sort + inspect extremes	df.describe()

Mini-Experiment Protocol

# EXPERIMENT: [Description]
# HYPOTHESIS: [What we expect]
# METHOD: [SQL query / TypeScript code / Python code]
# RESULT: [actual output]
# EXPECTED: [what we expected]
# STATUS: PASS / FAIL

Rules:

• One question per experiment
• Fast (< 30 seconds)
• Logged (print results)
• Compared with expectation

Cognitive Bias Prevention

• Do NOT analyze only first N records (survivorship bias)
• Do NOT look only for confirmations (confirmation bias)
• Analyze ALL data
• Actively look for DISPROOF of hypothesis