Statistical Questions?
Is this a statistical question? Why or why not?
No.
The data (yes or no response) does not vary!
What do we call a study in which the researcher/data collector passively observes values and records them?
An observational study.
The population.
When a sample is accurately indicative of the population, we describe it as _________.
Representative.
The sample and sampling frame are the same thing.
True or false? Explain.
False.
The sampling frame is the subset of the population that could end up in the sample. It is not the sample itself.
"On average, how many hours of screen time do you use per week?"
Is this a statistical question? Why or why not.
Yes!
The data collected will tend to vary from point to point.
A study in which the researcher actively records data that unfolds in real time is known as a __________ study.
A subset of the population from which we collect our data.
A sample.
Sampling frame.
In an ideal scenario, the sampling frame is identical to the population.
True or false? Explain.
True.
We want the sampling frame to be as close as possible to the population of interest. Otherwise we might inadvertently leave out subjects of interest or end up including subjects that have no business being in our sample.
Turn this into a legitimate statistical question by changing up the wording.
"How much money is in your wallet right now?"
"On average, how much cash do carry [every day/week/month/etc.]?"
A study in which the researcher actively records data that occurred in the past is known as a __________ study.
Retrospective study.
A method of data collection in which every member of the population is sampled.
We refer to this as a unknown value about the population that is almost never observed in practice (ex. - proportion of Bergen County adult residents who own their home).
Parameter
Convenience sampling does not always produce bias.
True or false?
False.
Convenience sampling always produces bias because it leaves out those who are less convenient to contact.
Turn this into a valid statistical question by changing up the wording.
"How many inches of rain did Emerson receive during the month of July 2026?"
True or false. Explain your reasoning.
"A prospective study is more meaningful than a retrospective study because the data being collected are more current."
False.
Meaningfulness of a study is not dependent on when the data were collected.
Meaningfulness of a study is dependent on how the data were collected.
This term is used to describe data collection in which every member of the population has an equal likelihood of being selected.
Random.
A value obtained from sampling the population that is intended to be a representative estimator of the population parameter.
Sampling error/sampling variability is a problem that must be addressed in order for a sample to be free from bias.
True or false. Explain.
False.
Sampling variability is a natural phenomenon that we expect as we record multiple observations. One sample should be expected to differ from one to another. In some cases, it might be desireable to reduce sampling variability if possible, but it is not possible to eliminate it.
True or false.
"A valid statistical question is always practically significant."
Explain your reasoning. Can you provide an example?
False.
A question for which the data vary does not necessarily imply that is of any practical importance (to anyone).
On average, how many sesame seeds are on a Big Mac hamburger bun?
True or false. Explain your reasoning.
"Observational studies are the gold standard with which to show a causal (cause-and-effect) relationship."
False.
Observational studies are capable of showing an association [or correlation if that association is linear], but they cannot show a causal link between two or more variabels.
This term describes a study in which the method of data collection would consistently under or overestimate the the value you want to know.
Bias.
This is known as the natural tendency for randomly drawn samples to differ from one another.
Sampling variability.
When a census is taken instead of a sample, inferences do not need to be made because the population parameters will be known.
True or false? Explain.
True!
Inferences are educated guesses based on a representative sample of a population.
If that population is sampled entirely, no guesses need be made.