Stat 100 Quiz 2
Terms
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- observational study
- the researcher observes what is happening or what has happened in the past and tries to draw conclusions based on these observations.
- experimental study
- the researcher manipulates one of the variables and tries to determine how the manipulation influences other variables.
- explanatory variable
- also known as the independent variable, in an experimental study is the one that is being manipulated by the researcher.
- outcome variable
- also called the dependent variable. A variable in correlation and regression analysis that cannot be controlled or manipulated.
- treatment group
- a group in an experimental study that has recieved some type of treatment.
- control group
- a group in an experimental study that is not given any special treatment.
- hawthorne effect
- when subjects knew they were participating in an experiment actually changed their behavior in ways that affected the results of the study.
- confounding variable
- one that influences the dependent variable but cannot be separated from independent variable.
- suspect samples
- researchers use very small samples to obtained information when a large sample size is better to do, and the selection of the subjects in the sample is important so there is not any built-in bias.
- Ambiguous Averages
- mean, median, mode, and midrange
- changing the subject
- statistical distortion can occur when different values are used to represent the same data.
- detached statistics
- no comparison is made. For example "Brand A telenol works 2 times faster." Faster than what?
- implied connections
- "Eating cherrios for breakfast may help reduce your cholestrol." The words MAY HELP signifies that there is no guarantee that eating cherrios for breakfast will for sure reduce your cholestrol.
- misleading graphs
- If graphs are drawn inappropriately, they can misrepresent the data and lead the reader to false connections.
- faulty survey questions
- when analyzing results of a survey using questionnaires, you should be sure that the questions are properly written since the way questions are phrased can often influence the way people answer them.
- mean
- the sum of the vaules, divided by the total number of values. symbol ( )
- median
- the midpoint of the data array. symbol (MD)
- mode
- the value that occurs most often in a data set
- midrange
- the sum of the lowest and highest values in the data set,divided by 2. symbol (MR)
- range
- the highest value minus the lowest value. symbol (R)