Critical Evaluation of Data

Critical Evaluation of Data

Lesson Objectives;

• ​Identify the key problems involved in selecting a sample.

• ​discuss how to avoid and reduce bias when sampling.

​Problems involved in sampling

​Read the google slides linked on the next slide describing some of the problems encountered in sampling, make some notes and respond to the proceeding quiz.

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The End ​

Multiple Choice

To learn about teenagers' opinions of different social media platforms, a survey was given to students of one high school. This sample is...

• representative

• biased

• random

Multiple Choice

An employer wants to know how their 500 employees like working for them. Which is the most representative sample?

• Ask the first 75 people to show up for work

• Randomly select the names of 10 employees

• Poll the Employees of the Month for the past year

• Randomly select the names of 75 employees

Multiple Choice

Which is an example of a random sample?

• Polling the first 10 people who enter a room

• Asking a survey question to people who call in

• Drawing 10 names from a hat

Multiple Choice

Why should samples be randomly selected?

• for control

• to reduce bias

• so we don't get the same answers from everyone

Multiple Choice

Political webpages often allow readers to rate (if they want to) whether they strongly agree, agree, disagree, or strongly disagree with the President's decision on any given situation. This is a form of:

• Self-Selected

• Convenience Sampling

• Simple Random Sampling

• Systematic Random Sampling

Multiple Choice

Unbiased sampling is:

• when you choose the group you think will give you the answer you want, accept volunteers or survey by convenience

• when any member of the population is equally likely to be chosen for the sample

Multiple Choice

To determine the most popular children’s programs, a television station asks parents to call in and complete a phone survey.

• Biased Sample

• Unbiased Sample

Multiple Choice

A school randomly chose ten English teachers and asked them which type of juice their students would prefer. Which reason best shows why this sample is biased?

• The sample didn't include students.

• The sample is too small.

• The sample can only be accurate if each teacher is included in the sample

Multiple Choice

The choir director in a high school wants to know how the students in the school feel about singing. If the director selects 100 girls and 100 boys to complete a survey, which method will result in a biased sample?

• The students will be selected from the choir

• The students will be selected randomly throughout the school

• The students will be selected on Wednesday afternoon before the choir concert

• The choir director will select five students from each of the forty homerooms in the school

Multiple Choice

A factory manufactures light bulbs. The factory currently has 300 boxes of light bulbs in its warehouse. To test the quality of bulbs, Alex decides to take out a sample of bulbs and test them to see if they work. Which surveying method will give him the least valid results?

• selecting ten boxes randomly, mixing the bulbs of these boxes together and then selecting ten bulbs randomly

• selecting ten boxes randomly and then selecting one bulb randomly from each box

• selecting one bulb randomly from every tenth box

• selecting one box randomly and then selecting all the bulbs from the box

Multiple Choice

In order to use samples to estimate something from the population, the sample should be _________________ the population.

• exactly the same as

• nothing like

• representative of

• larger than

Multiple Choice

What is sampling bias?

• Bias resulting when non-probability sample is drawn.

• Bias resulting from the inappropriate designation of eligibility criteria.

• Bias resulting from the use of probability sampling method.

• Bias resulting from over-representation or under-representation of population segments in a sample.