Chapter 1 Vocabulary Flashcards
Statistics
The science of collecting, organizing, summarizing, and analyzing
information to draw conclusions or answer questions. In addition, it is about
providing a measure of confidence in any conclusions.
Population
The entire group of individuals to be studied.
Individual
A person or object that is a member of the population being studied.
Stastic
A numerical summary of a sample.
Descriptive Statistics
consists of organizing and summarizing data.
Descriptive statistics describe data through numerical summaries, tables, and graphs.
Inferential statistics
uses methods that take a result from a sample,
extend it to the population, and measure the reliability of the result.
Parameter
The numerical summary of a population.
Varaibles
the characteristics of the individuals within the population.
Qualitative (Categorical) Vaiables
Allow for classification of individuals based on some attribute or characteristic.
Quantitative variables
provide numerical measures of individuals. The values of a
these variable can be added or subtracted, and provide meaningful results.
Discrete variable
a quantitative variable that has either a finite number of possible values or a countable number of possible values. (The term countable means that the values result from counting, such as 0, 1, 2, 3, and so on.) These variable cannot take on every possible value between any two possible values.
Continuous variable
a quantitative variable that has an infinite number of possible values that are not countable. This variable may take on every possible value between any two values.
Data
the list of observed values for a variable.
Qualitative data
observations corresponding to qualitative variables.
Quantitative data
observations corresponding to a quantitative variables.
Discrete data
observations corresponding to discrete variable.
Continuous data
are observations corresponding to a continuous variable.
A variable is at the nominal level of measurement if
the values of the variable name, label, or categorize. In addition, the naming scheme does not allow for the values of the variable to be arranged in a ranked or specific order.
A variable is at the ordinal level of measurement if
it has the properties of the nominal level of measurement, however, the naming scheme allows for the values of the variable to be arranged into a ranked or specific order.
A variable is at the interval level of measurement if
it has the properties of the ordinal level of measurement and the differences in the values of the variable have meaning. A value of zero does not mean the absences of the quantity. Arithmetic operations such as addition and subtraction can be performed on the values of the variable.
A variable is at the ratio level of measurement if
it has the properties of the interval level of measurement and the ratios of the values of the variable have meaning. A value of zero means the absence of the quantity. Arithmetic operations such as multiplication and division can be performed on the values of the variable.
explanatory variable
a variable whose value is thought to impact the value of a response variable.
response variable
the variable of interest in the outcome of a study.
observational study
measures the value of the response variable without attempting to influence the value of either the response or explanatory variables. That is, in an observational study, the researcher observes the behavior of individuals without trying to influence the outcome of the study.
designed experiment
If a researcher assigns the individuals in a study to a certain group, intentionally changes the value of an explanatory variable, and then records the value of the response variable for each group
Confounding
n a study occurs when the effects of two or more explanatory variables are not separated. Therefore, any relation that may exist between an explanatory variable and the response variable may be due to some other variable not accounted for in the study.