1.) nominal and ordinal 2.) ordinal, interval, and ratio

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1.) Nominal and Ordinal 2.) Ordinal, Interval, and Ratio 3.) False. Data at the ordinal level can be qualitative or quantitative. - PowerPoint PPT Presentation

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1.) Nominal and Ordinal2.) Ordinal, Interval, and Ratio3.) False. Data at the ordinal level can be qualitative or quantitative.4.) False. For data at the interval level, you can calculate meaningful differences between data entries. You cannot calculate meaningful differences at the nominal or ordinal level.5.) False. More types of calculations can be performed with data at the interval level than with data at the nominal level.6.) False. Data at the ratio level can be placed ini a meaningful order.

7.) Qualitative8.) Quantitative9.) Quantitative10.) Qualitative11.) Ordinal. Data can be arranged in order, but the differences between data entries make no sense.12.) Nominal. No mathematical computations can be made and data are categorized using names.13.) Nominal. No mathematical computations can be made and data are categorized by region.14.) Ratio. A ratio of two data values can be formed so one data value can be expressed as a multiple of another. 15.) Ordinal. Data can be arranged in order, but the differences between data entries are not meaningful.16.) Ratio. A ratio of two data values can be formed so one data value can be expressed as a multiple of another.17.) Ordinal18.) Ratio19.) Nominal20.) Interval

1.3 Data Collection and Experimental Design

Objectives:

• How to design a statistical study

• How to distinguish between an observational study and an experiment

• How to collect thru a survey or simulation

• How to design an experiment and create a sample.

Observational Study

The study does not attempt to influence the responses of the subjects (there is not treatment), the study is an observational study.

Example: Researchers conduct a study to find the U.S. public approval rating of the U.S. president. To perform the study, researchers call 1500 U.S. residents and ask them whether they approve or disapprove of the job being done by the president.

Experiment

The study applies a treatment to the subject, the study is an experiment.

Example: Researchers study the effect of vitamin D3 supplementation among patients with antibody deficiency or frequent respiratory tract infections. To perform the study, 70 patients receive 4000 IU of vitamin D3 daily for a year. Another group of 70 patients receive a placebo daily for one year.

http://www.youtube.com/watch?v=Z_OJzgkKe2A

What is a placebo?

It is a fake treatment.

Why would researchers use a placebo?

Talk to someone next to you and come up with at least one reason.

Experiment

Two Experimental Units

Treatment Group Control Group (treatment is applied) (No treatment is applied)

Gives the researchers a measurable effect.

For Example:

An experiment was performed in which diabetics took cinnamon extract daily while a control group took none. After 40 days, the diabetics who took the

cinnamon reduced their risk of heart disease while the control group experienced no change.

Determine whether the study is an observational study or an experiment.

Researchers study the effect of vitamin supplementation among patients with antibody

deficiency or frequent respiratory tract infections. To perform the study, 70 patients receive 4000 IU of vitamin daily for a year.

Another group of 70 patients receive a placebo daily for one year.

Because the study applies a treatment to the subjects, the study is an experiment.

Determine whether the study is an observational study or an experiment.

Researchers conduct a study to find the U.S. public approval rating of the U.S. president. To perform the

study, researchers call 1500 U.S. residents and ask them whether they approve or disapprove of the job being

done by the president.

Because the study does not attempt to influence the responses of the subjects (there is no treatment), the study is an

observational study.

Determine whether the study is an observational study or an experiment.

The Pennsylvania Game Commission conducted a study to count the number of elk in Pennsylvania. The

commission captured and released 636 elk, which included 350 cows, 125 calves, 110 branched bulls, and

51 spikes. Is this study an observational study or an experiment?

The study does not apply a treatment to the elk. This is an observational study.

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