Sampling with Random Tables

Using random tables, which contain sequences of random digits, is a technique employed in statistics to select a sample from a larger population. This method ensures that each member of the population has an equal chance of being selected, forming the basis of probability sampling.

Tippet's Method Explained

The specific technique of using random number tables or random digits generated by a computer to select a sample is commonly referred to as Tippet's method. Sir John Richard Nicholas Tippett developed tables of random numbers, and their use in sampling is named after him.

To use Tippet's method:

• Assign a unique number to each element in the population.
• Decide how many digits are needed based on the population size.
• Select a starting point in the random number table (randomly).
• Read off the required number of digits sequentially.
• Each set of digits corresponding to a population number identifies an element to be included in the sample.

Why Other Options Differ

The other options are distinct from using random tables:

• Simple Random Sampling: This is the broader category that Tippet's method falls under. While using random tables is one way to achieve simple random sampling, the term itself doesn't specifically refer to the use of tables.
• Lottery Method: This involves writing names or numbers on slips of paper, putting them in a container, and drawing them out randomly. It's a physical method, unlike using pre-printed or generated random number tables.
• Quota Sampling: This is a non-probability sampling method where researchers divide the population into subgroups and set quotas for the number of participants needed from each subgroup. Selection within the quota is often non-random.

Therefore, the use of Random tables for drawing a sample is specifically known as Tippet's method.