CIT MIDTERMS

• Data Presentation


  Data are usually collected in a raw format and thus the inherent information is difficult to understand. Therefore, raw data need to be summarized, processed, and analyzed to usefully derive information from them.
• Data Presentation


  Presentation of data refers to an exhibition or putting up data in an attractive and useful manner such that it can be easily interpreted.
• Three Main Forms of Data Presentation

  • Textual Presentation
  • Tabular Presentation
  • Graphical Presentation
• Textual Presentation


  All the data is presented in the form of text, phrases, or paragraphs. It involves enumerating important characteristics, emphasizing significant figures and identifying important features of data.
• Textual Presentation


  Text is the principal method for explaining findings, outlining trends, and providing contextual information.
• Textual Presentation


  • In the statistics class of 40 students, 3 obtained the perfect score of 50. Sixteen students got a score of 40 and above, while only 3 got 19 and below. Generally, more than half of the students in the class passed the test with 23 or 57.5% getting a passing score of 38 and above.
• Advantages of Textual Presentation

  • The data would be more interpreted.
  • Can help in emphasizing some important points in data.
  • Small sets of data can be easily presented.
• Tabular Presentation


  It is a systematic and logical arrangement of data in the form of Rows and Columns with respect to the characteristics of data. A table is best suited for representing individual information and represents both quantitative and qualitative information.
• Advantages of Tabular Presentation

  • More information may be presented.
  • Exact values can be read from a table to retain precision.
  • Flexibility is maintained without distortion of data.
  • Less work and less cost are required in the preparation.
• Parts of the Table

  Title, Boxhead, Stubs, Footnotes, Sources of Data
• Simple or One-way Table


  • Frequency Distribution Table
• Graphical Presentation


  A graph is a very effective visual tool as it displays data at a glance, facilitates comparison, and can reveal trends and relationships within the data such as changes over time, and correlation or relative share of a whole.
• Graphical Presentation


  It is considered an important medium of communication because we are able to create a pictorial representation of the numerical figures.
• Graphical Presentation


  Suited when we need to show the results of the study to nonprofessionals and or people who dislike numbers and too lengthy texts.
• Guidelines for Constructing Good Graphics

  • Title and label the graphic axes clearly, providing explanations if needed. Include units of measurement and a data source when appropriate.
  • Avoid distortion.
  • Avoid clutter, such as excessive gridlines and unnecessary backgrounds or pictures.
  • Don't distract the reader.
  • Avoid three dimensions.
  • Do not use more than one design in the same graphic. Let the data speak for themselves.
• Measures of Central Tendency - Mean, Median Mode
• Mean


  It is the sum of the data values divided by the number of data values. It is also called the average. It is appropriate only for data under interval and ratio scale measurement.
• Advantages of Mean

  • Simple to understand and easy to calculate.
  • It is rigidly defined.
  • It takes into account all the values in the series.
• Median


  It is the "middle observation" when the data set is sorted (in either increasing or decreasing order). The median divides the distribution into two equal parts.
• Advantages of Median

  • The median is not affected by the size of extreme values but by the number of observations.
  • It can be easily interpreted.
• Mode


  It is the most frequently occurring value in a list of data. It is sometimes called nominal average. It is an appropriate measure of average for data using the nominal scale of measurement. It is the only measure of central tendency used in both quantitative and qualitative data.
• Advantages of Mode

  • The mode is easy to understand.
  • Like the median, it is not greatly affected by extreme values.
• Measures of Relative Position - Quartile, Decile, Percentile
• Quantiles


  Quantiles are statistics that describe various subdivisions of a frequency distribution into equal proportions.
• Quartiles


  Quartiles - split the ordered data into four quarters.
• Deciles


  Deciles - split the ordered data into ten equal parts.
• Percentiles


  Percentiles - split the ordered data into one hundred equal parts.
• Mean


  The "center of gravity" of your data
• Median


  The "middle value" within your data
• Quartiles


  Split the ordered data into four quarters
• Deciles


  Split the ordered data into ten equal parts
• Percentiles


  Split the ordered data into 100 equal parts
• Quantiles


  Statistics that describe various subdivisions of a frequency distribution into equal proportions
• Measures of Relative Position

  • Quartiles
  • Deciles
  • Percentiles
• Percentile rank


  Percentage of scores less than or equal to a given score
• Range


  The difference between the largest and smallest observations in a data set
• Standard deviation


  A measure of how far away items in a data set are from the mean
• Variance


  Represents all data points in a set and is calculated by averaging the squared deviation of each mean
• Standard deviation is in the same units as the mean, so it is more easily interpretable than variance
• Skewness


  The degree of distortion from the symmetrical bell curve or normal distribution