Do now – identify the sampling method

Slides:



Advertisements
Similar presentations
Ch 4 - Designing Studies.
Advertisements

Ch 4 - Designing Studies.
Population We are almost always interested in knowledge about a population. We would have little interest in samples if we could always ask everyone.
Sampling is the other method of getting data, along with experimentation. It involves looking at a sample from a population with the hope of making inferences.
Chapter 41 Sample Surveys in the Real World. Chapter 42 Thought Question 1 (from Seeing Through Statistics, 2nd Edition, by Jessica M. Utts, p. 14) Nicotine.
Conducting A Study Designing Sample Designing Experiments Simulating Experiments Designing Sample Designing Experiments Simulating Experiments.
Chapter 8.  The attitudes held by a significant number of people on matters of government and politics.
1 Chapter 11 Understanding Randomness. 2 Why Random? What is it about chance outcomes being random that makes random selection seem fair? Two things:
Scientific Method Identify a Problem Formulate a Hypothesis Determine a Plan of Action Collect Information/Data Analyze Information/Data Interpret Findings.
Day 2- Bias. BIAS Sampling methods that tend to over or underemphasize some characteristics of the population are said to be biased. Many of the most.
How can data be used? Data can be used to:
Please get out materials for notes.
Populations and Samples
Sampling and Experimentation
The effects of physical activity on third grade math scores
Chapter 12 Sample Surveys
Cultural Sensitivity Training
Sources of Bias 1. Voluntary response 2. Undercoverage 3. Nonresponse
Warm Up Assume that you are a member of the Family Research Council and have become increasingly concerned about the drug use by professional sports.
Learning Goal: (S-IC.B.3)
Section 5.1 Designing Samples
AP Statistics Chapter 5 Section 1.
CHAPTER 4 Designing Studies
Bias and Error What can go wrong?.
Chapter 10 Samples.
By Veronica and ricardo
4.2 Day
Bias On-Level Statistics.
Chapter Statistics and Probability
Chapter 12 Sample Surveys
Chapter 5 Producing Data 5.1 Designing Samples
Inference for Sampling
Improving the Lives of Callers: Call Outcomes and Unmet Needs
Wednesday, October 19, 2016 Warm-up
Samples, Experimental , & Observational Studies
Samples, Experimental , & Observational Studies
Unit 1 Day 4 Biased or Unbiased in Sampling
Information from Samples
Federalist Papers Activity
The European Statistical Training Programme (ESTP)
Fundamentals of Statistics
Section 7.4 Cautions about Sampling
Introduction to Statistics
AP Stats – 4.1 Sampling and Surveys.
Chapter 12 part 2 Types of bias.
Chapter 12 Sample Surveys.
Sampling and Study Design
Should You Believe a Statistical Study?
WARM – UP Use LINE 5 of the random digit table. 30. The World Series.
Homeschooling Kelli Hoffman.
a) Coins b) Playing Cards c) Spinner d) Number Cube
Chapter 5: Producing Data
5.3 Errors.
Unit 10 Statistics Part 1.
Warmup.
MATH 2311 Section 6.1.
Methods of Psychological Research
Inference for Sampling
Chapter 5 Producing Data.
Samples, Experimental , & Observational Studies
Psychological Research Methods and Statistics
Do now Do now is posted on google classroom.
Chapter 4: Designing Studies
What do Samples Tell Us Variability and Bias.
AP Statistics Response Bias Project.
Mean vs Median Sampling Techniques
Designing Samples Section 5.1.
Randomization and Bias
Chapter 5: The analysis of nonresponse
Chapter 2 Sociologists Doing Research Section 1: Research Methods
Presentation transcript:

Do now – identify the sampling method 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. A sociologist conducts an opinion survey in a major city. Part of the research plan calls for describing and comparing the opinions of four different ethnic groups: African Americans, Asian Americans, European Americans, and Native Americans. For a total sample of 300, the researcher selects 75 participants from each of the four predetermined subgroups. A researcher has a population of 100 third grade children from a local school district from which a sample of 25 children is to be selected. Each child’s name is put on a list, and each child is assigned a number from 1 to 100. Then the numbers 1 to 100 are written on separate pieces of paper and shuffled. Finally, the researcher picks 25 slips of paper and the numbers on the paper determine the 25 participants.

Problems with Sample surveys Lesson 4.1 Day 3 Problems with Sample surveys

Objectives Explain how undercoverage, nonresponse, question wording, and other aspects of a sample survey can lead to bias.

Definitions Undercoverage: some people can’t be chosen or are less likely to be chosen (ex. Landlines) Nonresponse: people can’t be reached or refuse (ex. No answer, hang up) Response bias: Interviewer influences answer, wording of questions, people lie These all lead to bias!

*Voluntary response bias is when an invitation to be part of a survey is given and people decided whether or not to participate.  They were NOT specifically chosen by the researchers. *Nonresponse is when people ARE chosen by the researchers for the survey but the people do not complete the survey.

Introduce Project The Project:   You and your partner (or you by yourself) will design and conduct an experiment to investigate the effects of response bias in surveys.  You may choose the topic for your surveys, but you must design your experiment so that it can answer at least one of the following questions: Can the wording of a question create response bias? Does providing additional information create response bias?   Do the characteristics of the interviewer create response bias? Does anonymity change the responses to sensitive questions? Does manipulating the answer choices/order of answer choices change the response? Can revealing other peoples’ answers to a question create response bias?

proposal Proposal (25 points): The proposal is due: _______. The proposal will be worth 25% of the grade, so don’t treat it casually.   If the proposal isn’t approved the first time, you will need to resubmit it for a reduced grade.  You must attach the original proposal to any resubmissions. In your proposal, you should: Describe your topic and state which type of response bias you are investigating Describe how you will obtain your subjects in an unbiased manner (minimum sample size is 50). This must be practical!!  Your population does not need to be from school nor should you interrupt any classes. Describe what your questions will be and how they will be asked, including how you will incorporate the principles of a good experiment and avoid potentially confounding variables.  You should also indicate what your hypotheses are. Convince me that you have a good design!

Pick your partner You have the rest of class to think about your project proposal

Do Now You are on the staff of a member of Congress who is considering a bill that would provide government-sponsored insurance for nursing- home care. You report that 1128 letters have been received on the issue, of which 871 oppose the legislation. “I’m surprised that most of my constituents oppose the bill. I thought it would be quite popular,” says the congresswoman. Are you convinced that a majority of the voters oppose the bill? How would you explain the statistical issue to the congresswoman?

Do Now A researcher was interested in studying the effect of number of hours spent watching tv on children's aggression level. The children were randomly split in two groups varying ages 5-10. After a month of time has passed then researcher returned to their homes to record the number of hours spent watching tv and any changes in aggression level. The results were monitored by the families of the children. What could be a confounding variable?