Random number table
Topic: Economic Data: Census, NSS, Surveys and Statistical Tools · NCERT: Class 11, Ch 2 "Collection of Data"; Class 11, Ch 8 "Use of Statistical Tools"
Meaning
A random number table is a printed table of digits in random order. It helps pick a random sample without bias. First, give each unit in the population a number. Then read numbers off the table and select the units whose numbers come up. Tippett's table is a well-known example. Today, computer random-number generators do the same job.
Example
A locality has 300 households, numbered 001 to 300. To choose 30 of them, read three-digit numbers from the table. Keep each number between 001 and 300, and skip any number above 300 or already chosen, until you have 30 households.
Don't confuse with
- Lottery method: this does the same job by writing names on slips, mixing them and drawing by hand. A random number table replaces the slips with printed digits.
Related concepts
- Census
- Sample survey
- Population
- Sample
- Representative sample
- Population parameter
- Random sampling
- Non-random sampling
- Sampling frame
- Lottery method