Introduction to Statistics

• Statistics - is a scientific body of knowledge which deals with the collection, organization, presentation, interpretation, and analysis of data.
• Collection - refers to the gathering of information or data.
• Organization or Presentation - involves summarizing data in graphical, tabular, or textual forms.
• Analysis - involves describing the data using statistical methods and procedures.
• Interpretation - refers to the process of making conclusions based on the presented data.
• Descriptive statistics - is concered with the collection, organization and presentation of data in a form that everyone can understand. It is used to summarize important features of a data. Collection of data, construction of tables and graphs, and computations of measures fall in this branch of statistics.
• Inferential statistics - is concered with the formulation of conclusions or generalizations about a population based on the information contained in a sample drawn from the population
• Population - refers the complete set of individuals, objects, places, or events under study, such as the residents in Quezon City, the students in this school or the viewers of a particular TV show.
• Sample - is the small portion of a population. It is the subgroup, subset, or the representative of a population.
• Parameter - the numerical value that describes the characteristics of a population.
• Statistic - is an estimate of a parameter. It is a numerical value that describes the characteristic of a sample.
• Data - are facts, set of information, or observations under study. Data are gathered from a population or from a sample.
• Qualitative data - are data which can assume values that manifest the concept of attributes. These categories which differents according to the characteristics they posses.
• Quantitative data - are data which are numerical in nature. They indicate how much of a given characteristics of an individual, object, or event possesses.
• Variable - is a quantitaty which may take on different values. IT is a characteristic of a population or a sample which makes the members different from each other.
• Discrete variables - is a variable whose values are obtained through the process of counting. These are variables that can assume a finite number of values.
• Continuous variable - is a variable that does not fall under the category of discrete. These are variables that can be obtained through the process of measuring.
• Constant - is a quantitaty which does not vary or is fixed. It is a property or characteristic of a population or a sample which makes the member of the group similar to each other.
• Nominal - it is characterized by data consisting of names, labels, or categories as nominal means name only.
• Ordinal - it is characterized by data that may be arranged in some order but the difference between the da rta is either meaningless or cannot be determined.
• Interval - it is characterized by data that may be arranged in order and the intervals between the data can be determined. Data in this level do not have a starting point.
• Zero point - is an interval scale is arbitrary and negative values are considered.
• The interval level is also called scaled variables since they have unit of measurement.
• Ratio - data in this level possess all of the characteristics of the interval level with an addition of a true zeo point. Most measurements are classified in this level.