Exam 1 Flashcards
(97 cards)
measures the valve of the response variable without attempting to influence the value of wither the response or explanatory variables researcher observes the behavior of the individuals without trying to influence the outcome of the study
observational study
when the researcher signs the individuals in a study to a certain group, intentionally changes the value of the explanatory variable, and then records the value of the response variable for each group
designed experiments
a subset of a population
sample
the entire group to be studied
population
a person or object that is a member of the population being studied
individual
a numerical summary of a sample
statistic
consist of organizing and summarizing data
descriptive statistics
uses methods that take a result from a sample, extend it to the population, and measure the reliability of the result
inferential statistics
a numerical summary of a population
parameter
the characteristics of the individuals within the population
variables
allow for classification of individuals biased on some attribute or characteristic
qualitative, or categorical, variables
provide numerical measures of individuals; the values of this can be added or subtracted and provide meaningful results
quantitative variables
a way to look at and organize a problem so that it can be solved
approach
a quantitative variable that has either a finite number of possible values or a countable number of possible values; cannot take on every possible value between any two possible values
discrete variable
a quantitative variable that has a infinite number of possible values that are not countable; may take on every possible value between any two values
continuous variable
when the values of the variable name, label, or categorize; does not allow for the values of the variable to be arranged in a ranked or specific order
nominal level of measurement
a variable that has the properties of the nominal level of measurement, however the naming scheme allows for the values of the variable to be arranged in a ranked or specific order
ordinal level of measurement
a variable that has the properties of ordinal level of measurement and the differences in the values of the variable have meaning a value of zero does not mean the absence of the quantity; + and -
interval level of measurement
a variable that has rations of the values of the variable that have meaning; a value of zero means the absence of quantity; x and divide
ratio level of measurement
the information collected
explanatory variable
what is affected by the explanatory variable
response variable
this occurs in a study when the effects of two or more explanatory variables are not separated; meaning any relation that may exist between an explanatory variable and the response variable may be due to some other variable(s) not accounted for in the study
confounding
an explanatory variable that was not considered in a study, but it affects the value of the response variable in the study; typically related to explanatory variables considered in the study
lurking variable
These studies do not allow a researcher to claim causation, only association
observational studies