Sampling
Mrs. Herring, the principal at Brookfield Middle School, asked her teachers to participate in a study on teaching methods. She asked 100 Teachers their thoughts on the matter. What is the population?
All teachers at Brookfield
While designing a new dessert menu, the manager of a restaurant offered customers a coupon in exchange for completing a brief survey about their favorite desserts. 20 of the customers accepted the offer. What is the Sample?
Voluntary Response Sample
Gabriel wanted to understand how students felt about their work load in their classes. He surveyed the 72 top-ranking students in the high school.
Biased - This was a Judgement sample. This is undercoverage and response bias.
Mr. Altum asks a student their thoughts on his class
Biased - Leading question
The U.S. does a survey of everyone living in the U.S. every ten years. This is an example of:
Census
A sample of 2,000 was sought to estimate the average achievement in science of fifth graders in a city’s public schools. The average fifth grade enrollment in the city’s elementary schools is 100 students. Thus, 20 schools were randomly selected and within each of those schools all fifth graders were tested.
Cluster Random Sample
A sample of 30 students were randomly selected from a list of 100 by assigning each of them a number and using a random number generator to choose
Simple Random Sample
Jasper created a website and wanted to understand what people thought of the UI. He surveyed the first 48 people to use a new website.
Biased - He performed a convenience sample. This was undercoverage bias
Due to diminishing resources, should a law be made to require people to recycle?
Biased - Leading Question
The Idea that all answers vary and change on any given survey is:
Sampling variability
phone every 200th person who mails in a coupon as part of a money-back offer on the purchase of mineral water
Systematic Random Sample
Winston polled 47 winners of a contest where 200 people won. What is the sample?
The 47 winners
Susan wanted to get an understanding of what people thought of her cookies. She looked up all the bakeries in Houston and used a random number generator to choose 10. She then spent the next month selling her cookies at those bakeries and asking customers if they liked them.
Random- She performed a cluster sample
Outside of a Canes every 10th customer is asked "How would you rate todays costumer experience and the food you received?"
Biased - Double Barreled question
A __________ is to population as a __________ is to sample.
What is parameter, statistic
A restaurant manager wants to gauge the opinion of the restaurant’s customers. He walks around and interviews 20 people who are eating there one Saturday night.
Convenience Sample
A student had to complete their sampling project before class started. During lunch he decided to randomly choose students at different tables.
Judgement Sample
Mrs. Castillo wanted to determine if students were ready for a test. She took the names of every student she had and put them in a hat and drew them randomly
Random - she performed a simple random sample
A researcher wanted to know what people thought of their current sleep schedule. He went around and gave people a survey that included the question:
How many hours do you sleep a night?
a. 1-8
b. 8-10
c. 10-12
d. >12
Biased - Poor answer choices
What are the 3 biased sampling techniques?
Voluntary response, Convenience, Judgement
Without looking, Eduardo flipped to a page in the phone book and called a number from that page. Repeating that approach, he called 843 phone numbers from the phone book.
Judgement Sample
A researcher is interested in maximum-security inmates. She groups inmates by the type of crime committed, determines the percentage of the total in each crime category, and uses that percentage to determine the number of inmates randomly selected from each group.
Stratified Random Sample
Gabriel is in college studying Spanish and wanted to determine if the school is producing students fluent in Spanish. He decided to go ask the two Spanish 100 classes and asked everyone in those classes.
Biased - He performed a judgement sample. This was undercoverage bias
Students at Mayde Creek High School wanted to try and do a survey. They went around asking students "On a scale of 1-10 what what would you rate being a student athlete?"
Biased - Loaded Question and poor answer choices
What are the 4 good sampling techniques?
Simple Random, Stratified Random, Systematic Random, and Cluster random