FACTS ABOUT STATISTICS

Statistics of Class 8

FACTS ABOUT STATISTICS

Statistics - a set of concepts, rules, and procedures that help us to:

Organize numerical information in the form of tables, graphs, and charts;
Understand statistical techniques underlying decisions that affect our lives and well-being; and Make informed decisions.

Data - facts, observations, and information that come from investigations.
Measurement data sometimes called quantitative data -- the result of using some instrument to measure something (e.g., test score, weight);
Categorical data also referred to as frequency or qualitative data. Things are grouped according to some common property(ies) and the number of members of the group are recorded (e.g., males/females, vehicle type).
Variable - property of an object or event that can take on different values. For example, college major is a variable that takes on values like mathematics, computer science, English, psychology, etc.
Discrete Variable - a variable with a limited number of values (e.g., gender (male/female), college class (freshman/sophomore/junior/senior).
Continuous Variable - a variable that can take on many different values, in theory, any value between the lowest and highest points on the measurement scale.
Independent Variable - a variable that is manipulated, measured, or selected by the researcher as an antecedent condition to an observed behavior. In a hypothesized cause-and-effect relationship, the independent variable is the cause and the dependent variable is the outcome or effect.
Dependent Variable - a variable that is not under the experimenter's control -- the data. It is the variable that is observed and measured in response to the independent variable.
Qualitative Variable - a variable based on categorical data.
Quantitative Variable - a variable based on quantitative data.