Assessment 5 Instructions: Evaluating Studies

Evaluate a statistical study.

Introduction

In this assessment, you will demonstrate your ability to critically evaluate surveys and their statistical findings. In the process, you will get to know important terms and methods that are used when conducting a survey and when presenting a report based on an evaluation of a survey and its statistical findings.

Demonstration of Proficiency

By successfully completing this assessment, you will demonstrate your proficiency in the following course competencies through the following assessment scoring guide criteria.

• Competency 2: Evaluate the adequacy of data collection methods.
  • Assess the appropriateness of a sample to represent a population.
  • Explain the rationale for using a particular sampling technique.
• Competency 5: Evaluate statistical arguments.
  • Interpret the meaning of the confidence interval in the context of survey results.
  • Evaluate the impact of question wording on participants’ responses.
  • Evaluate a study for evidence of bias.

This assessment is somewhat independent of the other assessments so far, in the sense that it does not involve your own survey. Instead, you will produce a report based on an evaluation of a Gallup survey and its statistical findings. Gallup reports on a variety of polls with explanations of the survey methods. Categories of polls include politics, economy, well-being, health care law, taxes, federal budget, and many other subjects.

For Assessment 5, you need to select a survey from Gallup then analyze it. You will find links to the most recent topics on the Gallup home page. https://www.gallup.com/home.aspx   You can search for surveys by keyword; alternatively, click on the news link at the bottom of the page and search by topic. Make sure the topic you select contains information about survey methods, particularly the sample size, sampling method, and margin of error.

To prepare for this assessment, go to the Gallup home page and do the following:

• Review a variety of polls on the site. https://www.gallup.com/home.aspx
• Choose a poll to report on that closely aligns to your field of study or area of professional interest.
• Review the information in the Survey Methods section of the article. This section details how the study was conducted. Also, study all information contained in additional links at the bottom of this section. You will use this information to complete your assessment.

Then, answer the following questions about the Gallup poll you selected:

• What was the purpose of the poll? Write a brief summary. Include the title and link to the article within your summary.
• What were the population and sample? Why is this sample appropriate for the population? What was the sample size? Was the sample size large enough to reflect the opinions of the population?
• Were the results parameters or statistics? Why?
• What type of sampling technique was used (for example, stratified, clustered, random, convenience, or systematic)? Why was this technique used? How were the subjects contacted? Was this method appropriate?
• What was the confidence interval and margin of error? Interpret what the confidence interval means as it relates to the context of the survey.
• What were the exact questions asked? Do you think the wording of the questions influenced the participants’ responses?
• Did you find any evidence of bias in the poll? If so, describe the source of the bias. If not, how was bias avoided?