NGPF 9.8 Evaluating Statistical Claims

What is the recovery % for Treatment 1?

What is the recovery % for Treatment 2?

What recommendation would you give about the two treatments from only this data?

• Research is inconclusive; further research is needed before making a recommendation.

• Treatment 1 is more effective because more patients recovered after using Treatment 1.

• Treatment 2 is more effective because more patients recovered after using Treatment 2.

• Both treatments are equally effective; recommend either treatment.

• Treatment 2 is more effective because less patients recovered after using Treatment 2.

Imagine you received further detailed results from the study.

You know that severe cases have a lower rate of recovery than minor cases no matter what treatment type you use.

● Of the 500 patients assigned Treatment 1, 400 had a minor case and 100 had a major case.

● Of the 500 patients assigned Treatment 2, 50 had a minor case and 450 had a major case.

What percentage of the patients with Treatment 1 had a major case of the illness?

Imagine you received further detailed results from the study.

You know that severe cases have a lower rate of recovery than minor cases no matter what treatment type you use.

● Of the 500 patients assigned Treatment 1, 400 had a minor case and 100 had a major case.

● Of the 500 patients assigned Treatment 2, 50 had a minor case and 450 had a major case.

What percentage of the patients with Treatment 2 had a major case of the illness?

Imagine you received further detailed results from the study.

You know that severe cases have a lower rate of recovery than minor cases no matter what treatment type you use.

● Of the 500 patients assigned Treatment 1, 400 had a minor case and 100 had a major case.

● Of the 500 patients assigned Treatment 2, 50 had a minor case and 450 had a major case.

With this new information, how would your conclusions change about the two treatments from this additional data?

• Research is still inconclusive; more further research is needed before making a recommendation.

• Treatment 2 is more effective at treating both major and minor illnesses because the recovery percentage for both types of illnesses is higher for Treatment 2 than Treatment 1.

• Treatment 1 is more effective because more patients recovered after using Treatment 1 when considering both major and minor illnesses.

• Both treatments are equally effective on both major and minor illnesses; recommend either treatment.

• Treatment 1 is more effective because less patients recovered after using Treatment 1 when considering both major and minor illnesses.

Match the definitions with their vocabulary terms.

• Parameter

• Looking at the data only one way does not give the whole picture, also called Simpson's Paradox

• Association Reversal

• A measurement or characteristic from a sample

• Selection Bias

• An error that occurs when the sample is not an accurate representation of the population

• Sampling Error

• The difference between sample and population

• Statistic

• A measurement or characteristic from a population

You may want to know what the average starting salary is for a graduate with a Bachelor’s degree. You could ask 1000 recently graduated students from a nearby university what their starting salary is and find the average, or you could just ask your brother who recently graduated what his salary is.

Instead of your brother, you ask one other random graduate their starting salary. Would you expect their salary to be close to your brother’s salary? Why or why not?

• Yes, because all graduates have similar starting salaries.

• No, because starting salaries can vary widely among graduates.

• Yes, if they are in the same field and location.

• No, unless they have negotiated the same terms.

• Yes, you get what you get and don't get upset

Imagine you received further detailed results from the study.

You know that severe cases have a lower rate of recovery than minor cases no matter what treatment type you use.

● Of the 500 patients assigned Treatment 1, 400 had a minor case and 100 had a major case.

● Of the 500 patients assigned Treatment 2, 50 had a minor case and 450 had a major case.

Calculate the recovery % and complete the table for the patients divided by subgroups.

h

c

d

g

5%

50%

36%

76%

42%

10%

20%

70%

90%

80%

Imagine you received further detailed results from the study.

You know that severe cases have a lower rate of recovery than minor cases no matter what treatment type you use.

● Of the 500 patients assigned Treatment 1, 400 had a minor case and 100 had a major case.

● Of the 500 patients assigned Treatment 2, 50 had a minor case and 450 had a major case.

What is a major difference between the groups that would result in Treatment 1 appearing more effective when the data is taken as one group?

• Treatment 1 was mostly made up of minor cases while Treatment 2 was mostly made up of major cases.

• Treatment 1 had a larger sample size than Treatment 2.

• Treatment 2 was applied more consistently than Treatment 1.

• There is no significant difference; it's a matter of data interpretation.

• Treatment 2 had a smaller overall sample size than Treatment 1.