nivek

• Statistics


  A term which has several meanings, can be singular or plural depending on usage
• Statistics


  • Branch of Science which deals with the collection, presentation, analysis and interpretation of results
• Collection of Data


  Data gathering using one or combination of following methods: interview, questionnaire, registration or observation
• Presentation of Data


  Organization of data into tables, graphs or charts so that the reader will be able to get the clear picture of the various relationships
• Analysis of the Data

  Process of extracting relevant information from the given data
• Interpretation of Data


  Drawing conclusions from the analyzed data
• Descriptive statistics


  • Only concerned with summarizing values to characterize data gathered from a sample or population
  • Employs graphs, tables, measures of central tendency, and position and variability
  • Does not attempt to draw conclusions about anything that pertains to more than the data themselves
• Inferential statistics


  • Concerned with making generalizations from information gathered from a small group of observations or from a sample to a bigger group of observations or to a population
• Population


  The totality of elements under consideration in statistical investigation
• Parameter


  The specific characteristic of the population is described using the summary measure
• Sample


  A subset of population
• Statistic


  The specific characteristics of sample is described using summary measure
• Census

  Process which refers to when information or data are gathered from all units of the population
• Sample Survey


  Process when a part of the population is used to obtain data
• Variable


  A characteristic, description, or attribute of persons or objects which assumes different values or labels
• Classification of Variables


  • Qualitative
  • Quantitative
• Qualitative


  Yields categorical responses. Answers, " What kind"
• Quantitative


  Yields numerical responses representing an amount or quantity. Answers, " How much" or " How many"
• Classification of Quantitative Variables

  • Discrete
  • Continuous
• Discrete


  Pertains to the principle of counting (no. of students, no. of patients)
• Continuous


  • Assumes values which are associated with points on an interval of the number line
  • Also pertains to the process of measurement with corresponding units (height, weight, temperature, etc.)
• Levels of Measurement


  • Nominal Level
  • Ordinal Level
  • Interval Level
  • Ratio/Scale Level
• Nominal Level


  This is characterized by data that consists of names, labels or categories only
• Ordinal Level


  This involves data that arranged in some order, but differences between data
• Interval Level


  This is the same in ordinal level, with an additional property that we can determine meaningful amounts of differences between the data
• Ratio/Scale Level


  This is the highest level of measurement. All the properties of the interval scale are applicable in the ratio scale plus the presence of the "true zero point" which reflects the absence of the characteristics measured
• Nominal Level


  • types of cars, gender of respondents
• Ordinal Level


  • degree of effectiveness, satisfactory evaluation
• Interval Level


  • IQ score, temperature (Fahrenheit, Celsius)
• Ratio/Scale Level


  • age, income, examination scores
• Measure of Central Tendency


  A value that describes a set of data by identifying the central position within that set of data
• Three Measures of Central Tendency

  • Mean
  • Median
  • Mode
• Mean


  The most common measure of central tendency. It is simply the sum of all score divided by the number of scores
• Weighted Mean


  A variation of mean that assigns weights to the individual scores before getting the average
• Median


  The middle value in the distribution after arranging the data either in ascending or descending order
• Mode


  The most frequently occurring value
• Negatively Skewed


  Mean & mode located at the right
• Positively Skewed

  Mean & mode located at the left
• Normal Distribution


  Mean, mode & median located at the center
• RANGE

  • The most basic among the measures of dispersion