Mr. Smith has identified two groups of students to participate in his study examining the effectiveness of using algebra tiles. One group will use these manipulatives while a second group will receive a traditional lectu
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Mr. Smith has identified two groups of students to participate in his study examining the effectiveness of using algebra tiles. One group will use these manipulatives while a second group will receive a traditional lecture approach. Both groups are then assessed with the same exam. Which test should be used to test the differences in exam marks between the mean scores for the two classes? Why? - Answer>>> Independent t-test because we are comparing mean scores across two unrelated groups of students. Extra points if you mentioned that before conducting this test you would have to check that the assumptions hold.
When to use a Welch's t-test? - Answer>>> When testing two variables with unequal variance and unequal sample sizes
What measures would you use to summarize a distribution - Answer>>> could report mean and SD/variance. To give an idea of the spread, you might also report min/max and the IQR.
Explain what the standard error of the mean is and how it is estimated. What happens to the SE when the sample size increases? - Answer>>> The standard error of the mean measures the uncertainty in estimate of the mean. This is calculated by dividing the standard deviation by the square root of the sample size. The larger the sample size, the smaller the SE
When is a variable confounding? - Answer>>> When it is associated with both the exposure and the outcome, and is not on the causal pathway
What is the difference between a confounding variable and an effect modification? - Answer>>> Confounding- where a third variable can bias the observed association between exposure and an outcome.
The actual counts in the cells of a contingency table are referred to as the expected cell frequencies - Answer>>> False, they are observed cell frequencies
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