Random Sampling Methods

Every possible group of units of the required size has the same chance of being the selected sample as any other sample of the same size.

• Simple Random 

• Thoughtful

• Typical

• Proportional

This sample is selected by dividing the population into subgroups and then taking a fixed number of units from each group using the simple random sample.

• stratified

• cluster

• judgment

• experimental

Identify the sampling design: Student government randomly samples 25 students of each of the four classes.

• stratified

• volunteer

• systematic

• simple random

Identify the sampling design: Mr. Rhoades puts all of his students' names in a hat and randomly selects one without looking.

• cluster

• volunteer

• systematic

• simple random

Interview every 10th student who enters the school in the morning.

• simple random

• voluntary response

• systematic

• convenience

A teacher wants to know how well her students are doing on a topic. She randomly picks one class to survey.

• Simple Random

• Cluster

• Stratified

• Systematic

Units of the population are grouped; one or more groups are selected at random.  All units of that group are included in the sample.

• cluster sample

• simple random

• stratified

• proportional

Identify the sampling design: The LFCC registrar wants to investigate attitudes of their graduates.  The registrar randomly selects 100 names from each of the four past graduating classes.

• cluster

• volunteer

• stratified

• simple random

The names of 70 contestants are written on 70 cards. The cards are placed in a bag and three names are picked from the bag.

• Random

• Convenience

• Systematic

• Voluntary

You are interested in finding out the percent of residents in the city that have experienced a robbery in the past year. Using the city property records, you assign each residence a number. You use a random number generator to give you a list of numbers. You contact the residence that corresponds to that number to ask your questions.

• Random

• Stratefied

• Systematic

• Cluster