Value of Statisticss

The discipline of statistics is the scientific study of numerical data based on variation in nature. It is "scientific" because data collection and analysis should be objective and follow scientific methodology. Statistics are used to provide empirical evidence that tends to support or refute theories used in science; statistics are mathematical methods that basically allow us to understand data. Statistics have four main functions: 1.) Description, 2.) Inference, 3.) Measurement of relationships, and 4.) Probability.

Descriptive statistics transforms large groups of numbers into a more manageable form and gives characteristics of a set of data. This type of statistics includes measures of central tendency, which tell you the most typical or representative score in a set of data. The three most frequently used measurements of central tendency are the mean, the mode, and the median. Another type of descriptive statistic includes measures of variation or dispersion, such as, the range, variance, and the standard deviation.

Inferential statistics are methods used to generalize characteristics from a set of data to a larger population. The researcher obtains data from a group of subjects, which is called the sample. The sample is thought of as having come from a larger group of subjects, which is called the population. Although the researcher is interested in characteristics of the population, only the sample data is available. With inferential statistics the researcher uses the sample data to make scientific inferences about the population.

Measurement of relationship is a type of statistical procedure used to determine whether there is a relationship between two or more factors, which are present in a situation, and how strong their relationship is. For example, if we measured the height and weight of 100 people and found that the tallest people generally weighed the most and the shortest people weighed the least, we would say that a positive relationship exists between the variables of height and weight. Not all correlations are positive. Some correlations or relationships are negative while others have no relationships or have a zero correlation.

Probability is a formal study of the laws of chance. Statistics, a branch of mathematics, springs from the gambling tables. Since outcomes of events cannot be predicted perfectly, methods of probability make precise the degree of predictability and indicate the chance occurrence of an event.