Parameter

Definition

A parameter is a characteristic or value that defines the conditions, limits, or properties of a statistical model, experiment, or analysis. It is a numerical or quantitative measure that helps describe and understand the behavior of a system or phenomenon.

5 Must Know Facts For Your Next Test

1. Parameters are often unknown and must be estimated from sample data, whereas statistics are calculated directly from the sample data.
2. Parameters describe the characteristics of a population, while statistics describe the characteristics of a sample.
3. The process of using sample data to estimate the value of a population parameter is known as statistical inference.
4. Parameters can be fixed, such as the slope of a regression line, or random, such as the mean of a normal distribution.
5. The accuracy of parameter estimates depends on the size and representativeness of the sample, as well as the underlying assumptions of the statistical model.

Review Questions

• Explain the difference between a parameter and a statistic, and how they are used in the context of statistical analysis.
  • A parameter is a numerical measure that describes a characteristic of a population, while a statistic is a numerical measure calculated from a sample of data. Parameters are often unknown and must be estimated using statistical inference, whereas statistics are directly calculated from the sample data. Parameters are used to model and understand the behavior of a population, while statistics are used to make inferences about the population based on the sample data.
• Describe the role of parameters in the context of statistical models and how they are used to make inferences about a population.
  • Statistical models use parameters to describe the underlying structure and characteristics of a population. These parameters, such as the mean, variance, or regression coefficients, define the properties of the model and how it is expected to behave. By estimating the values of these parameters from sample data, researchers can make inferences about the population, including making predictions, testing hypotheses, and quantifying the uncertainty associated with their conclusions. The accuracy of these inferences depends on the assumptions of the statistical model and the quality of the sample data used to estimate the parameters.
• Analyze how the concept of parameters is related to the definitions of statistics, probability, and other key terms in the context of 1.1 Definitions of Statistics, Probability, and Key Terms.
  • The concept of parameters is central to the definitions of statistics and probability, as well as other key terms in the 1.1 Definitions chapter. Parameters describe the characteristics of a population, which is the focus of statistical analysis and probability theory. Samples are drawn from the population, and statistics calculated from these samples are used to estimate the unknown parameters. The process of using sample data to make inferences about population parameters is at the heart of statistical inference, a core component of the field of statistics. Additionally, the concepts of probability distributions and their parameters, such as the mean and variance, are essential for modeling and understanding the behavior of random variables and phenomena.

Related terms

Statistic: A statistic is a numerical summary or measure calculated from a sample of data, used to estimate or infer the value of a corresponding parameter in the population.

Population: The entire group or set of items, individuals, or measurements that are the focus of a statistical study or analysis.

Sample: A subset of the population that is selected and studied to make inferences or estimates about the characteristics of the entire population.