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Best Practices

Expert tips for effective model testing, evaluation, and deployment.


Testing Strategy

1. Start Simple

Begin with defaults:

  • Temperature: 0.7
  • Max Tokens: 500
  • Single model (GPT-4o Mini)

Why: Establish a baseline before optimization.

2. Test Systematically

Change one parameter at a time:

Test 1: Default settings
Test 2: Change temperature only
Test 3: Change max tokens only
Test 4: Combine best settings

Don't: Change everything at once (can't identify what works).

3. Use Real Data

Test with actual use case prompts:

  • Real customer questions
  • Actual data to analyze
  • Production-like scenarios

Leverage prompt history:

  • Review what prompts worked before
  • Re-run successful tests
  • Track performance over time

Don't: Only test with toy examples.


Sample Size

Minimum Test Runs

Use CaseMin TestsWhy
Classification50Need statistical significance
Content Generation10Check consistency
Customer Support20Vary user intents
Data Analysis15Test edge cases

Testing Pattern

// ✅ Good: Multiple runs
for (let i = 0; i < 20; i++) {
result = testModel(prompt, settings);
results.push(result);
}
analyze(results);

// ❌ Poor: Single test
result = testModel(prompt, settings);
deployToProduction(); // Risky!

Evaluation Criteria

Define Success Metrics

Before testing, define:

  1. Quality Threshold

    Customer Support: 90% helpful responses
    Code Generation: 95% syntactically correct
    Data Classification: 98% accuracy
  2. Performance Requirements

    Response Time: < 2 seconds
    Token Usage: < 500 tokens average
    Cost per Request: < $0.01
  3. Consistency Standard

    Same input should yield similar quality
    Variation acceptable: ±10%

Measure Objectively

Quantitative Metrics:

  • Accuracy (for classification)
  • Response time (milliseconds)
  • Token count (cost proxy)
  • Word count (length)
  • Completion rate

Qualitative Assessment:

  • Relevance (1-5 scale)
  • Clarity (1-5 scale)
  • Professionalism (1-5 scale)
  • Accuracy (1-5 scale)

Model Selection

Decision Framework

1. Quality Requirements
High (>95%) → GPT-4 Omni
Medium (85-95%) → GPT-4o Mini
Basic (70-85%) → GPT-3.5 Turbo

2. Volume Considerations
Low (<1K/day) → Any model
Medium (1K-10K/day) → GPT-4o Mini or GPT-3.5
High (>10K/day) → GPT-3.5 Turbo + selective GPT-4

3. Budget Constraints
Premium → GPT-4 Omni
Standard → GPT-4o Mini
Economy → GPT-3.5 Turbo

Hybrid Approach

Best Practice: Use multiple models

function selectModel(request) {
// Complex reasoning → Premium model
if (requiresDeepAnalysis(request)) {
return "GPT-4-Omni";
}

// Standard questions → Mid-tier
if (isStandardQuery(request)) {
return "GPT-4o-Mini";
}

// Simple tasks → Economy
return "GPT-3.5-Turbo";
}

Parameter Optimization

Temperature Testing

Test at 3 points:

Low: 0.3
Medium: 0.7 (default)
High: 1.2

Choose based on:

  • Consistency needed? → Use 0.3
  • Balanced? → Use 0.7
  • Creativity needed? → Use 1.2

Token Limit Optimization

Find the sweet spot:

// Test different limits
tokenLimits = [200, 400, 600, 800, 1000];

for (limit of tokenLimits) {
result = test({maxTokens: limit});
if (result.complete && result.cost < budget) {
optimalLimit = limit;
break;
}
}

Cost Management

Monitor Token Usage

Track these metrics:

metrics = {
avgInputTokens: 150,
avgOutputTokens: 300,
totalTokens: 450,
costPerRequest: 0.008,
requestsPerDay: 1000,
dailyCost: 8.00
}

Optimization Strategies

  1. Prompt Optimization

    ❌ Verbose: "I would like you to please help me by..."
    ✅ Concise: "Summarize this text:"

    Savings: 20-30% fewer input tokens
  2. Token Limits

    ❌ No limit: Average 800 tokens
    ✅ Set limit: 400 tokens

    Savings: 50% on output costs
  3. Model Routing

    ❌ All GPT-4: $300/month
    ✅ Mixed models: $80/month

    Savings: 73%

Quality Assurance

Pre-Deployment Checklist

  • Tested with 20+ real prompts
  • Success rate > threshold
  • Response time acceptable
  • Cost within budget
  • Edge cases handled
  • Error handling tested
  • Monitoring in place

Continuous Testing

After deployment:

// Monitor production
setInterval(() => {
metrics = collectMetrics();

if (metrics.quality < threshold) {
alert("Quality degradation detected");
}

if (metrics.cost > budget) {
alert("Budget exceeded");
}
}, 3600000); // Check hourly

Common Mistakes

❌ Mistake 1: Testing Only Once

Problem: Single test doesn't show consistency

Solution: Run minimum 10 tests per configuration

❌ Mistake 2: Using Wrong Model

Problem: GPT-4 for simple classification (expensive)

Solution: Match model capability to task complexity

❌ Mistake 3: Ignoring Edge Cases

Problem: Works for normal inputs, fails on unusual ones

Solution: Test with:

  • Empty inputs
  • Very long inputs
  • Special characters
  • Multiple languages
  • Ambiguous requests

❌ Mistake 4: No Cost Analysis

Problem: Production costs explode unexpectedly

Solution: Calculate costs before scaling:

Cost per Request × Requests per Day × 30 = Monthly Cost

❌ Mistake 5: Skipping Documentation

Problem: Can't reproduce or explain results

Solution: Document:

  • Test configurations
  • Success criteria
  • Results and metrics
  • Rationale for choices

Pro Tip: GenAI Explorer's prompt history automatically documents your tests! Export the history for comprehensive records.


Testing Template

Use This Structure

## Test: [Test Name]

**Date:** [Date]
**Tester:** [Name]

### Configuration
- Model: GPT-4o Mini
- Temperature: 0.7
- Max Tokens: 500
- Top P: 1.0

### Test Cases
1. [Test case 1]
- Input: [prompt]
- Expected: [expected output]
- Actual: [actual output]
- Pass/Fail: [result]

### Metrics
- Success Rate: 85%
- Avg Response Time: 1.8s
- Avg Cost: $0.006
- Token Usage: 450 avg

### Analysis
- Strengths: [what worked well]
- Weaknesses: [what didn't work]
- Recommendations: [next steps]

### Decision
[ ] Deploy as-is
[ ] Needs optimization
[ ] Try different model

Advanced Tips

1. A/B Testing

Test two approaches simultaneously:

Group A: GPT-4 Omni, temp 0.5
Group B: GPT-4o Mini, temp 0.7

Compare: Quality, Cost, Speed
Winner: Based on your priorities

2. Prompt Versioning

Track prompt iterations using the built-in prompt history:

v1.0: Original prompt → Saved in history
v1.1: Added examples → Compare with v1.0
v1.2: Clarified format → See improvement
v1.3: Optimized tokens (20% reduction) → Best version

GenAI Explorer automatically saves all versions - just browse your history to compare!

3. Automated Testing

// Run automated tests
testSuite = [
{prompt: "test1", expected: "result1"},
{prompt: "test2", expected: "result2"},
// ...
];

results = runTests(testSuite, model, settings);
report = generateReport(results);


Follow these best practices to ensure successful AI model testing and deployment.