lesson 2

• Data Collection Methods

  • Interview Method
  • Questionnaire Method
  • Registration Method
  • Experimental Method
  • Observation Method
  • Texting Method
• Interview Method


  The researcher makes direct and personal contact with the interviewee and gathers data by asking a series of questions
• Questionnaire Method


  The researcher distributes the questionnaires either personally or by mail and collects them by the same process
• Registration Method


  This method of collecting data is governed by existing laws. The researcher gathers data from offices concerned
• Experimental Method


  This method is used to find out the cause and effect relationship of certain phenomena under controlled conditions
• Observation Method


  The researcher may observe subjects individually or in groups to obtain data and information related to the objectives of the investigation
• Texting Method


  The researcher may ask or invite individuals to text opinions on certain issues or send in their choices on brand preferences using their cellphones
• Sources of Data

  • Primary Sources
  • Secondary Sources
• Primary Sources


  Government offices, private organizations, establishments and recognized individuals who have firsthand information about an event
• Secondary Sources


  Newspapers, journals and magazines
• Sampling Techniques

  • Probability Sampling
  • Non-Probability Sampling
• Probability Sampling Techniques

  • Lottery Sampling
  • Table of Random Numbers
  • Systematic Sampling
  • Stratified Sampling
  • Cluster Sampling
  • Multi-Stage Sampling
• Lottery Sampling


  Also known as raffle, each member of the population is numbered on a piece of paper
• Table of Random Numbers


  A table of random numbers, invented by a statistician, is used to draw the numbers for the sample
• Systematic Sampling


  This is done by numbering each element of the population
• Stratified Sampling


  We obtain samples by dividing the population into strata (groups) and selecting the sample proportionately from each stratum
• Cluster Sampling


  Also called area sampling, we select members of the sample by area and then select each area by lottery sampling
• Multi-Stage Sampling


  We use combinations of several random sampling techniques to get the sample from a very large population
• Non-Probability Sampling Techniques

  • Convenience Sampling
  • Quota Sampling
  • Purposive Sampling
• Convenience Sampling


  This is used because it is convenient for the researcher
• Quota Sampling


  The researcher uses the proportions of the different strata and from the strata, selections are done using quota
• Purposive Sampling


  The researcher gets his sample from the respondents purposely related or close to him
• Ways of Organizing Data

  • Grouped Data
  • Ungrouped Data
• Grouped Data


  Organized and arranged into class intervals presented in a frequency distribution form
• Ungrouped Data


  Not organized and may or may not be arranged according to their magnitude
• Presentation of Data Methods

  • Array Form Method
  • Textual Form Method
  • Stem and Leaf Presentation
  • Tabular Form Method
  • Frequency Distribution Table
• Array Form Method


  An array is a rectangular arrangement of objects in equal rows (horizontal) and equal columns (vertical)
• Textual Form Method

  Also called paragraph method, is used to present purely qualitative data or if there are only very few numerical data
• Stem and Leaf Presentation

  Stem represents the first digit(s) and leaf represents the last digit
• Tabular Form Method

  Statistical tables are effective devices of presenting both qualitative and quantitative data. The tables can be used conveniently to make comparisons and draw relationships between and among variables
• Frequency Distribution Table


  Grouping of all data into interval/classes, showing values and frequency
• Steps to construct a Frequency Distribution Table


  1. Find the range

  2. Determine the number of classes

  3. Determine the class size

  4. Select a starting point and construct the table

  5. Construct the class intervals or class limits

  6. Make a tally of the data

  7. Determine the class boundaries

  8. Determine the less than and greater than cumulative frequencies and calculate the percentage of the relative frequencies
• Graphs of Frequency Distribution

  • Frequency Polygon
  • Histogram
  • Pareto Chart
  • Less Than Ogive and Greater Than Ogive Graph
  • Pie Chart or Circle Chart
  • Pictograph
  • Scatterpoint Graph/Scatter Diameter
  • Line Graph
  • Component Bar Chart
  • Statistical Maps