Basic Concepts

FRM Array

An FRM array is a binary data format for storing results of sociological and marketing research.

Each array consists of: - ✅ Questionnaires — respondent answers - ✅ Questions (signs/variables) — list of survey questions - ✅ Alternatives — answer options for each question

Question Types

Type	Description
qm	Metric — numeric value (age, income, rating)
qn	Nominal — single answer from options (gender, city, education)
qj	Multi-variant — multiple answers simultaneously (product usage, information sources)

Questionnaire Structure

Each questionnaire has a fixed size in bytes. Questions are stored sequentially one after another.

💡 Limitation: Maximum size of a single questionnaire is 30,000 bytes