Contextualization

Theoretical Introduction

Census and sample surveys are two of the most important statistical methodologies used for data collection and analysis. Both have their particularities and are applicable in different scenarios.

The census survey, also known as data collection, is a method of gathering information where all elements of the universe in question are considered. In the case of the Demographic Census carried out by IBGE, for example, all inhabitants of Brazil are interviewed to obtain a broad view of the Brazilian population.

On the other hand, the sample survey collects data from a representative sample of the universe in question. This sample is selected to reflect the characteristics of the total population, allowing conclusions to be drawn from this portion. The sample survey is often used when it is unfeasible or inefficient to interview the entire universe, whether for financial, time, or logistical reasons.

Contextualization

The importance of understanding the methodologies of census and sample surveys is evident in various areas of everyday life. It is through these techniques that we organize our understanding of the society in which we live. Governments, companies, and research institutes use these methodologies to make decisions that impact our daily lives.

For example, imagine a company that wants to launch a new product in the market. To understand the needs of consumers and whether the product will be well-received, it is impossible to interview all potential customers. Therefore, a sample survey will be conducted. Similarly, governments conduct censuses to create public policies according to the characteristics of the population.

Practical Activity

Activity Title: "Ask the 7th Grade"

Project Objective

Use census and sample survey techniques to collect and analyze data about the 7th-grade students at school. The data obtained will be used later to develop a statistical "profile" of the class.

Project Description

Groups will create and conduct a survey about the 7th-grade students at school. The survey will be conducted in two stages. In the first stage, they will conduct a census survey with the students in their own classroom. In the second stage, they will conduct a sample survey with students from the other 7th-grade classes.

The questionnaires can address different aspects of their classmates' lives, such as musical preferences, sports activities, career aspirations, etc. The goal is to better understand the 7th-grade universe and, thus, uncover patterns and trends.

Required Materials

• Notebook for notes
• Pens
• Computer with internet access (for research and creating spreadsheets)
• Spreadsheet software (Microsoft Excel, Google Sheets, etc.)

Step by Step

1. Form Groups: Groups should consist of 3 to 5 students, with each member having a specific role (e.g., coordinator, reporter, researcher, analyst, and presenter).

2. Develop the Questionnaire: Groups should create a questionnaire with questions they find interesting to better understand their classmates. The questionnaires must be approved by the teacher before implementation.

3. Conduct the Census Survey: Groups should administer the questionnaire to all students in their classroom and record the responses.

4. Conduct the Sample Survey: Now, groups should randomly select a representative sample of the 7th-grade universe (excluding their class) and administer the same questionnaire.

5. Analyze the Data: Groups should analyze the data obtained from the census and sample surveys, make comparisons, and interpret the results.

6. Prepare the Report: The group must write a detailed report containing all required elements: Introduction, Development, Conclusions, and Bibliography used.

7. Present the Results: Each group must present the results to the class, discussing the conclusions drawn from the surveys.

Project Deliverables

Students must submit the written report, following the suggested structure, and the spreadsheets with the survey results. In addition, students must make in-class presentations discussing their conclusions.

In the written report, the Introduction should introduce the theme and relevance of census and sample surveys. In the Development section, they should detail the questionnaire development, survey implementation, data analysis, and results discussion. In the Conclusion, students should reflect on the learning acquired from the project. Finally, in the Bibliography, they should reference the sources consulted.

Note that the report should be coherent and well-linked to the practical activity, providing details of the survey itself and the interesting discoveries the group made, as well as the conclusions drawn about their classmates and the comparison between the sample and census survey data.

The project should be carried out over a week, with a workload of 2 to 4 hours per student.