Vocab
A subset of individuals in the population from which we collect data.
What is a sample?
A sample chosen in such a way that every group of individuals in the population has an equal chance to be selected as the sample.
What is a Simple Random Sample?
Used to provide a baseline for comparing the effects of other treatments.
What is a control group?
Some news organizations maintain a database of customers who have volunteered to share their opinions on a variety of issues suppose that one of these databases includes 9000 registered voters in California to measure the amount of support for a controversial ballot issue. 1000 registered voters in California are randomly selected from the database and ask their opinion, what is the largest population to which the result of the survey should be generalized?
The 9000 registered voters from California in the database.
Did Mr. Tolman go to T-1(second kindergarten)?
What is yes?
A specific condition applied to the individuals in an experiment.
What is a treatment?
A sample selected by randomly choosing groups and including each member of the selected groups in the sample.
What is Cluster Sampling?
When experimental units are assigned to the treatments completely at random.
What is a Completely Randomized Design?
To gather information about the validity of a new standardized test for the 10th grade students in the particular state a random sample of 15 high schools was selected from the state. A new test was administered to every 10th grade student in the selected high school. What kind of sample is this?
What is a cluster random sample?
If a general invitation is sent out and responses are recorded, what type of bias does this lead to.
What is voluntary response bias?
This measures an outcome of a study. (Hint: Y variable)
What is a response variable?
A sample consisting of individuals from the population that are easy to reach.
What is Convenience Sampling?
Random assignment of experimental units to treatments carried out separately within each block.
What is a Randomized Block Design?
Professor Lee has a large collection of pennies that she uses for activities with her Statistics students. To estimate the average age of the pennies in her collection, she asks Luke to select a random sample of 20 pennies. To avoid getting his hands dirty, Luke selects 20 of the shiniest pennies from the collection what type of bias is present and how is the estimated average age different from the actual average age of the pennies.
Undercoverage, the estimate will be too small.
Which generation is Mr. Tolman from.
What is Gen X?
This may help explain or predict changes in a response variable.
What is an explanatory variable?
A sample selected from an ordered arrangement of the population by randomly selecting one of the first individuals and choosing every nth individual thereafter.
What is Systematic Sampling?
When an observed difference in responses between the groups in an experiment is so large that it is unlikely to be explained by chance variation in the random assignment.
What is Statistically Significant?
Can a vegetarian or low salt diet reduce blood pressure? Subjects with high blood pressure are assigned at random to one of four diets, (1) normal diet with unrestricted salt (2) vegetarian diet with unrestricted salt (3) normal diet with restricted salt (4) vegetarian diet with restricted salt. How many factors does this experiment have?
For an experiment, when individuals are randomly selected, but not randomly assigned can inferences be made about the population or cause and effect.
What is the population?
When two variables are associated in such a way that their affects on a response variable cannot be distinguished from each other.
What is confounding?
A sample selected by choosing an SRS from each stratum and combining the SRS’s into one overall sample.
What is Stratified Random Sampling?
A common experimental design for comparing two treatments that uses blocks of size 2.
What is a Matched Pairs Design?
Corn variety 1 yielded 140 bushels per acre last year at a research farm. This year corn variety two planted in the same location yielded only 110 bushels per acre. Based on these results is it reasonable to conclude that corn variety 1 is more productive than corn variety 2.
No, because there may be other differences between the two years besides the corn variety.
Mr. Tolman’s middle name.
What is David?