Statistical hypothesis test

1. For a statistical hypothesis test, there are two possible outcomes and two possibilities for the right answer, yielding four possibilities in total (this was explained in the first pre-recorded video of Modules:Wk 9).

List the four terms for these possibilities (4 marks)

2. To fully open the b s, a high percentage of Australians must be vaccinated.

For 8 marks, write what the above sentence claims for what is necessary and what is sufficient to fully open the b s.

3. “People who eat chard are slimmer than people who don’t eat chard.”

3A. For 3 marks, state the three causal model types (as spoken about in the pre-recorded videos) that can explain the correlation. Use X, Y, and Z in your answer. Number them 1, 2, and 3.

3B. For 6 marks, for each of the causal models 1, 2, and 3 that you listed above, write a complete sentence, describing the causal model without jargon (no X’s or Y’s) in terms of the actual content of the quoted sentence.

3C. For 4 marks, describe a specific third factor that might explain the correlation and how could it explain it? (it’s ok if you already mentioned it above)

4. Research Finds Jobs Makes One Happier Than Marriage

What’s the secret to happiness? It’s an age-old question that is addressed in a new study. A team of researchers analyzed data from over 1.7 million people worldwide to uncover the keys to happiness across the human life span. Interestingly, they found employment to be a stronger predictor of happiness than marriage. “For all measures and regions, employed people had higher subjective well-being than unemployed people,” state the researchers. “The effects were larger than for marriage.”

4A For 4 marks, describe the causal model the above passage suggests in a complete sentence without any jargon (no “X”s or “Y”s or “Z”s).

4B. For 4 marks, is the study likely to be an experiment or an observational study? Why?

4C. For 6 marks, without using jargon such as X and Y, describe an alternative causal model that could plausibly explain the finding.

5. If you have a state ID, you can register for that event.

The above sentence implies something about necessary and sufficient conditions for being able to register for that event. For 4 marks, rewrite this sentence, using the words necessary and/or sufficient in the sentence.

6. People who frequently watch old movies have a higher annual death rate than people who don’t. A newspaper article reporting on the research implies that you should stop watching old movies, as that will reduce your risk of death.

6A. For 4 marks, without using jargon such as X and Y, describe an alternative causal model that could plausibly explain the finding. Explain how this model is plausible.

6B. For 6 marks, concoct a research study designed to test whether listening to old music elevates the risk of death.

7. Six hours blindfolded results in diriabrosis, and I’m not going to blindfold myself. That’s why I’m not going to get diriabrosis.

7A. For 3 marks, rewrite the above as a syllogism in standard form, labelling the premises and conclusion.

7B. For 4 marks, is the conclusion suppositionally inescapable? Why?

7C. For 2 marks, is the conclusion inescapable? Why not?

8. An observational study finds that men who mention that they play darts on their online dating profiles get fewer women contacting them than men who don’t. Stephen Smith concludes that a mention of playing darts makes women less interested.

For 8 points, describe an experiment to test Stephen’s conclusion.

9. Truth contingency tables are described in Modules:Wk9. Consider the following truth table:

For 4 points, write two if-then sentences that together match the truth table.

10. A prerecorded video (Modules:Wk 9) explained a comic strip (https://xkcd.com/882/) about jelly beans and acne.

For 4 marks, in your own words, explain why we should not conclude that jelly beans cause acne, even though the null hypothesis was rejected for one color of jelly beans.

11. Canadian chocolate is not good. Because Mountie chocolate is Canadian, it’s not good.

For 3 marks, rewrite the above as a syllogism in standard form, labelling the premises and conclusion.

12. A newspaper headline is: “Superdrinks that make you stronger”.

The article underneath the headline lists a bunch of drinks.

For 3 marks, does the headline make a correlational or a causal claim? Explain why you think this.

13. What statistical technique was described in class as sometimes useful to separate out the effects of multiple measured variables? (2 marks)
14. Many headlines of articles about epidemiological studies, such as about nutrition, later are found to be false. Why is that? (2 marks)
15. A daycare assesses the amount of virus on employees’ hands when they leave work with a chemical test. Unfortunately, a better assay found that the chemical test detected the virus in only half of the cases where the employee truly had virus on their hands.

For 3 marks, write a sentence about what you know about the chemical test, in terms of “sensitivity” or “specificity”.

16. The park does not have slugs when there’s a blue-tongue living there, and the park did not have slugs last year. There must have been a blue-tongue living there.

16A. For 6 marks, in 35 words or less rewrite as a syllogism, with premises and a conclusion.

16B. For 3 marks, is the park argument suppositionally inescapable? Explain your answer.