Chapter 5 Sampling and Surveys

Slides:



Advertisements
Similar presentations
Chapter 7: Data for Decisions Lesson Plan
Advertisements

Chapter 5 Producing Data
Section 7.3 – Simple Random Samples
Chapter 5 Data Production
AP Statistics Section 5.1 Designing Samples. In an observational study, we simply observe individuals and measure variables, but we do not attempt to.
Section 1 Part 1. Samples vs Population  Benefits of getting data from the entire population….  You can draw a conclusion about the entire population….more.
AP Statistics.  Observational study: We observe individuals and measure variables of interest but do not attempt to influence responses.  Experiment:
Chapter 5 Sampling and Surveys
Section 2-1 Samples, Good and Bad. Remember: We select a sample in order to get information about some population (entire group of individuals about which.
Chapter 7: Data for Decisions Lesson Plan Sampling Bad Sampling Methods Simple Random Samples Cautions About Sample Surveys Experiments Thinking About.
Chapter 5 Section 1: SAMPLES. Read p. 201 Sample #1: American Idol wants to decide their next winner. They do this through a call-in poll. They get a.
Chapter 5 Section 1 – Part 2. Samples: Good & Bad What makes a sample bad? What type of “bad” sampling did we discuss previously?
CHAPTER 8: Producing Data Sampling ESSENTIAL STATISTICS Second Edition David S. Moore, William I. Notz, and Michael A. Fligner Lecture Presentation.
CHAPTER 8: Producing Data Sampling ESSENTIAL STATISTICS Second Edition David S. Moore, William I. Notz, and Michael A. Fligner Lecture Presentation.
Designing Samples Chapter 5 – Producing Data YMS – 5.1.
PUT THE FOLLOWING TEST SCORES IN ORDER AND GROUP THEM INTO FOUR GROUPS; Question of day.
AP STATISTICS Section 5.1 Designing Samples. Objective: To be able to identify and use different sampling techniques. Observational Study: individuals.
Lecture PowerPoint Slides Basic Practice of Statistics 7 th Edition.
Chapter 5 Sampling: good and bad methods AP Standards Producing Data: IIB4.
I can identify the difference between the population and a sample I can name and describe sampling designs I can name and describe types of bias I can.
SAME SEATS!!! You will be able to choose an SRS using a table of random digits and using technology. Today’s Objectives:
Kinds of Samples Statistics is still fun. Random – Choose your population - 7 th graders/7 th grade teachers/7 th grade parents. – Put all the names in.
Types of Samples. Samples Population – the main group or set from which observations or opinions can be made Sample – a small part of a population from.
Chapter 5 Sampling and Surveys. Section 5.1 Samples, Good and Bad.
Designing Studies In order to produce data that will truly answer the questions about a large group, the way a study is designed is important. 1)Decide.
Chapter 5: Producing Data 5.1 – Designing Samples "An approximate answer to the right question is worth a good deal more than the exact answer to an approximate.
AP Statistics C5 D1 HW: p.285 #19-24 Quiz in 2 class days Obj: to choose a simple random sample Do Now: What is the difference between a sample and a population?
CHAPTER 8: Producing Data Sampling ESSENTIAL STATISTICS Second Edition David S. Moore, William I. Notz, and Michael A. Fligner Lecture Presentation.
Section 1 Part 1 Chapter 5.
Chapter 5 Data Production
Essential Statistics Producing Data: Sampling
Chapter 4: Designing Studies
Section 5.1 Designing Samples
Chapter 5 Sampling and Surveys
CHAPTER 12 Sample Surveys.
Chapter 12 Sample Surveys
Collecting Data-Sampling
CHAPTER 8: Producing Data: Sampling
Chapter 12 part 1 Sample surveys.
Section 5.1 Designing Samples
Sampling and Surveys How do we collect data? 8/20/2012.
Who do I ask, what do I ask them, what does that tell me?
Chapter 7 Special Topics
A way of collecting, organizing, and interpreting data
Producing Data Chapter 5.
Chapter 12 Sample Surveys.
1.2 Sampling LEARNING GOAL
CHAPTER 8: Producing Data: Sampling
Warm Up Imagine you want to conduct a survey of the students at Leland High School to find the most beloved and despised math teacher on campus. Among.
Daniela Stan Raicu School of CTI, DePaul University
Designing Samples Section 5.1.
Chapter 4: Designing Studies
Essential Statistics Producing Data: Sampling
Section 5.1 Designing Samples
Chapter 5: Producing Data
5.1 – Designing Samples.
MATH 2311 Section 6.1.
Chapter 5: Producing Data
Sample Design Section 4.1.
Basic Practice of Statistics - 5th Edition Producing Data: Sampling
Chapter 4: Designing Studies
Chapter 4: Designing Studies
Chapter 3 producing data
Chapter 4: Designing Studies
Do Now For your senior project, you are studying first generation college graduates. You are interested in knowing what percent of KIPP students will.
10/15/ A Samples and Surveys.
Designing Samples Section 5.1.
Randomization and Bias
EQ: What is a “random sample”?
Presentation transcript:

Chapter 5 Sampling and Surveys 5.1 Samples, Good and Bad

Bias Samples Sample is a small group from a larger population. Design flaw of a statistical study that systematically favors certain outcomes. Systematically favoring one outcome over another Samples Sample is a small group from a larger population. Representative samples have the same characteristics of the larger population

BIASED SAMPLES: Voluntary Response Sample Individuals choose to become part of the sample by responding to a general request. Very biased in that many reply with extreme or strong opinions on the subject matter. Not a representative sample since not all people would choose to respond. EX: Call-in, write-in, putting out a flyer asking for participants, etc.

BIASED SAMPLE: Convenience Sample Selection of individuals that are easily obtained. Not a representative sample. Example: choosing your 10 friends that you happen to see that day Selecting the first 10 names on a list of participants

Unbiased Sample Simple Random Sample (SRS) Sample of size n from a population chosen in such a way that: Every individual of the population has the same chance of being selected Every possible sample of size n has the same chance of being selected.

Example: 4 Students need to be selected to represent the class in Statistics Conference in Cancun during Spring Break. Put everyone’s name in hat, mix it up, and select 4 names. Put all the boy’s names in one hat and all the girl’s names in a second hat. Randomly select 2 boys and 2 girls. X

How to take a SRS: Table of Random Digits (table B)- A long string of digits (0-9) with the following properties: Each digit in the table is equally likely to be any of the 10 digits The entries are independent of each other. So knowing one digit doesn’t affect what the next one is.

HOW TO USE THE TABLE: 1) LABEL * Label each individual in your population with a # * Each # given must have the same amount of digits 2) TABLE * Go to the table, read across in groups that are the same size as the numbers you assigned

How to write instructions for SRS: Label each (person) with # (01) -- ____ Read across TRD, every digits represents a (person) . Ignore #’s , and repeats The first numbers are our sample

EXAMPLE: Take a sample 5 from the following list. Start at line 131 in the table. Smith Jones Holloway DeNizzo David Adams Schaefer Gray Capito Meyers Gingrich Card Dietrich Moreland Hall Walsh Whitter Jordan

Instructions Label each person with #01-18 Read across the TRD, every 2 digits represents a person Ignore 19-99,00 and repeats The first 5 numbers are our sample

First, label each person with a number, starting at 01 EXAMPLE: First, label each person with a number, starting at 01 01 Smith 07 Jones 13 Holloway 02 DeNizzo 08 David 14 Adams 03 Schaefer 09 Gray 15 Capito 04 Meyers 10 Gingrich 16 Card 05 Dietrich 11 Moreland 17 Hall 06 Walsh 12 Whitter 18 Jordan

* Next, read across table every 2 digits and circle numbers between 01 and 18, ignoring repeats, til you find 5 numbers. Line 131: 05|00|7 1|66|32| 81|19|4 1|48|73| 04|19|7 8|55|76| 45|19|5 9|65|65 Line 132: 68|73|2 5|52|59| 84|29|2 0|87|96| 43|16|5 9|37|39 31|68|5 9|71|50 Line 133: 45|74|0 4|18|07| 65|56|1 3|33|02 |07|05|1

Find the people you selected by matching up the numbers selected: EXAMPLE: Find the people you selected by matching up the numbers selected: 01 Smith 07 Jones 13 Holloway 02 DeNizzo 08 David 14 Adams 03 Schaefer 09 Gray 15 Capito 04 Meyers 10 Gingrich 16 Card 05 Dietrich 11 Moreland 17 Hall 06 Walsh 12 Whitter 18 Jordan