Descriptive statistics 1

• What are the steps in the research process?

  1. Ask a question
  2. Review literature
  3. Formulate hypothesis
  4. Choose methods
  5. Collect data statistics
  6. Analyse data statistics
  7. Interpret results statistics
  8. Communicate findings (research report)
• What is the purpose of descriptive statistics?

  To describe the data
• What do descriptive statistics include?

  Frequency, central tendency, dispersion, and position
• What is the role of inferential statistics?

  To test hypotheses
• What factors determine the type of inferential test used?

  Type of data, type of scale, type of relationship, and number of groups
• What are the two main types of data?

  Categorical and continuous
• What is categorical data?

  Data that consists of discrete groups or categories
• What is continuous data?

  Numbers that can take any value on a measurement scale
• What is a frequency distribution?

  • Determines the smallest and largest scores in a data set
  • Counts how many times each score is present
• What is a frequency histogram used for?

  To plot ordinal, interval, and ratio data
• What does a bar chart represent?

  It is used to plot nominal data
• What does the presence of spaces between bars in a bar chart indicate?

  That there is no continuous scale on the x-axis
• What is grouping in frequency distribution?

  • When the range is large, scores are grouped into larger chunks
  • Helps in simplifying data representation
• How is the shape of a frequency distribution interpreted?

  It starts with the shape of the distribution
• What is a uni-modal distribution?

  A distribution with a clear peak in the center
• What is a bi-modal distribution?

  A distribution with two clear peaks
• What characterizes a normal distribution?

  It is symmetrical about the middle position
• What is a skewed distribution?

  A distribution with one central peak that is not symmetrical
• What is a positive skew?

  A distribution with a long tail to the right of the highest value
• What is a negative skew?

  A distribution with a long tail to the left of the highest value
• What are the measures of central tendency in frequency distribution?

  • Mode: the most common value in a data set
  • Median: the score corresponding to the mid-point of the data set
  • Mean: the sum of all scores divided by the number of scores
• What is the mode in a data set?

  The most common value in a data set
• What is the median in a data set?

  The score corresponding to the mid-point of the data set
• How is the median defined in terms of score distribution?

  50% of scores lie above the median, 50% lie below
• What is the mean in a data set?

  The sum of all scores divided by the number of scores
• What type of data is the mean applicable to?

  Interval data