Jamhuri ya Muungano wa Tanzania

Ofisi ya Taifa ya Takwimu

Takwimu kwa Maendeleo
FREQUENT ASKED QUESTIONS (FAQS)

1. What is Data?

Data is a set of facts systematically collected and expressed in numerical form to achieve a pre-determined purpose.

2. What is data used for?

Data is used for analysis, planning, decision-making, administration, planning and project implementation and monitoring and evaluation.

3. What are the Types of Data?

There are two types of data: Primary data which are collected from the units of individual respondents directly for a given purpose; and Secondary data which had earlier been collected and statistically processed by other people / agencies, and are again used for another purpose. Secondary data is usually obtained from Yearbooks, Census Reports, Survey Reports, official records or reported experimental findings.

4. How does NBS determine what statistical data to collect?

Since NBS collects data to inform planning and decision-making at the various levels, data collection is demand-driven. Those demanding for the data to be used (users) guide NBS on what are required.

5. What is a Census?

A total enumeration of all units of statistical interest in the universe/area. NBS had conducted Population and Housing Censuses in 1967, 1978, 1988, 2002, 2012.

6. What is a Sample?

A portion of all the units of interest.

7. What is a Sampling Frame?

A sampling frame is the list of all elements or sampling units consituting a population under study. The sampling units may be individuals , households, blocks of houses etc. A sampling frame is a pre-requisite for selection of a representative sample.

8. What is a Survey?

A statistical activity involving collection of data from a sample for purposes of making inferences and conclusions about all the units of interest.

9. What is a Baseline Survey?

A survey setting benchmarks for future references.