Metrics:

Case Studies:

Guidelines for conducting and reporting case study research in software engineering.Link

What passes as a rigorous case study?.Link

Controlled Experiments:

A Controlled Experiment for Evaluating the Impact of Coupling on the Maintainability of Service-Oriented Software.Link

Assessing the maintainability of software product line feature models using structural metrics.Link

Can we evaluate the quality of software engineering experiments?.Link

Reporting guidelines for controlled experiments in software engineering.Link

Survey:

Principles of survey research: part 1: turning lemons into lemonade. Link

Principles of survey research part 2: designing a survey. Link

Principles of survey research part 4: questionnaire evaluation. Link

Principles of survey research: part 5: populations and samples. Link

Principles of survey research part 6: data analysis. Link