What is statistics?
Statistics comprises the arithmetic procedures to organize, sum up and interpret information.
Definitions and explanations of the most important terms generally associated with Introduction to Statistics
Statistics comprises the arithmetic procedures to organize, sum up and interpret information.
A variable is a characteristic or condition that is changeable, or has different values for different individuals, for example age.
An independent variable is a variable that is being manipulated by the researcher. It often comprises two or more conditions, to which participants are being exposed. The dependent variable is the variable that is being observed after manipulating the
...A discrete variable comprises different categories. For example, a class can consist of 18 or 19 children, but can not consist of 18.5 children. For a continuous variable, there are infinite numbers or values possible between two observed values. Think for example of length
...With descriptive research, the behavior, thoughts and feelings of a group of individuals are described.
With correlational research, the association between variables is studied. With correlational studies, no statements can be made about cause-and-effect relationships.
In experimental studies, a variable (the independent variable) is manipulated to examine its possible effects on behavior (the dependent variable). If this is true (and all other assumptions are met), we can conclude that the independent variable causes these changes. The
...This type of design is used when researchers are, for whatever reason, not able to manipulate the variable. Think for example of gender and age. The researcher studies the effects of a variable of an event that happens naturally and can not be manipulated. Quasi-experiments
...The research process comprises seven steps:
Select a topic.
Demarcate and specify the topic. Study prior research with regard to your topic and specify the research question(s).
Set up a plan to answer the research
Descriptive statistics is used to describe the data. We can calculate the mean, display the data in a graph or look for extreme scores. Inferential statistics refers to making inferences about the population, based on a certain
...When a measurement refers to the whole population, it is called a parameter. When a measure refers to the sample, it is called a statistic. Statistics are thus estimates of the parameter.
The simplest (lowest) measurement level is the nominal scale. For nominal variables, numbers only refer to categories. Measurement on the nominal scale categorize and label observations. The number 1 for example can be used for ‘men’ and the number 2 can be used for ‘women
...An ordinal variable comprises a set of categories with an ordering. For example, you can order the participants of a singing competition of worst to best on the basis of the applause they received. However, we can not determine perfectly how much more applause one or the
...An interval variable is a variable with a real number. Equal differences between number on this scale reflect equal differences in strength. However, with interval variables, there is no defined zero point. For example, you can not say a person has zero height. Because there
...A ratio variable is a variable with a real number. Equal differences between number on this scale reflect equal differences in strength. Here, we do speak of a zero-level. Because of this, we are able to add, subtract, multiply and divide observations. Examples of ratio
...Explanations, glossary and practice questions with fundamental concepts and tips, explanations and examples per topic when encountering, understanding and applying statistics
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