The informal research paper structure is sometimes used when writing essays or short research pieces; these examples of assignments won’t have as much structure as a formal research paper. But always make sure to review the assignment instructions or ask for any clarification from the professor regarding structure-specific questions. You always want to clearly understand what is required of you.
As a review, the list below are terms used when describing patterns of presenting information that might require a less formal paper structure:
discussions of raw data
summaries and abstracts
Look here for a refresher on these patterns: Chapter 3, “Thinking Strategies and Writing Patterns”