Sampling Methods Sampling Methods n n n Convenience

Sampling Methods

Sampling Methods n n n Convenience – use the easiest group you have access to Random – Picked by a random method Systematic – pick every kth person Stratified – Separate according to characteristics – then pick some from each group (a few from all) Cluster – pick all from a couple of groups (all from a few)

What type of sampling method is used? Each student puts a number in the hat and then a drawing is held. Random Sampling

Survey statistics students to see if they had enough time to take the test. We randomly pick some of the schools that took the test & every student at the selected schools are surveyed. Cluster Sampling

Put a big ad in the newspaper asking people to log their opinions on the PTA web site. Convenience Sampling

Randomly select one of the elementary schools and contact every parent by phone. Cluster Sampling

Send a survey home with every student, and ask parents to fill it out and return it the next day. Convenience Sampling

Randomly select 20 parents from each elementary school. Send them a survey, and follow up with a phone call if they do not return the survey within a week. Stratified Sampling

Hold a PTA meeting at each of the 20 elementary schools and tally the opinions expressed by those who attend the meetings. Stratified Sampling

Go through the district’s enrollment records, selecting every 40 th parent. PTA volunteers will go to those homes to interview the people chosen. Systematic Sampling

Randomly select two members from each baseball team in the league to represent the city all-star team. Stratified Sampling

Homework n Worksheet