PSY2 – Research Methods: Lesson 16

Descriptive Statistics Part 3 – Distributions

PSY2 RM PowerpointTeachers or students who want the original PPT please tweet @psychopepper

Learning Objectives

  • To KNOW and UNDERSTAND what the different types of distributions are.
  • To APPLY this knowledge of distributions to past exam questions.
  • To APPLY understanding of all descriptive statistics to grasshead project.
  • To EVALUATE understanding of key concepts so far.

Lesson Outline:


  1. Choose longest blade of grass for each grasshead.  Add to the board and calculate the appropriate measures of central tendency, dispersion and draw the appropriate graph.
  2. To take notes in booklet in the three distributions.
  3. To daw a diagram of what each of these looks like in booklet and annotate with measures of central tendency.
  4. Complete past exam questions on distributions in booklet and peer assess.
  5. Complete an “easy” concepts test of twenty concepts covered so far, teacher reads out the definition you name the concept.

Content Recap:

Normal Distribution: A symmetrical spread of frequency data that forms a bell shaped pattern. The mean, median and mode are all located at the highest peak


Positive Skewed Distribution: A non-symmetrical spread of frequency data where data clusters in the tail to the positive end (right). Left to right is the mode (located at the highest peak) then the median, then mean.



Negative Skewed Distribution: A non-symmetrical spread of frequency data where data clusters in the tail to the negative end (left). Left to right is the mean, then the median, then the mode (located at the highest peak).




If you would like to access PsychoPepper’s Glossary of Terms please click here

Study Notes (TBC):

If you would like to download a set of study notes for this lesson, you can do so here. If you would like access to the original word file please tweet @psychopepper


I would suggest that you have a copy of one of the textbooks which will allow you to read around the subject matter, pre-read ahead of lessons or even take extra notes/practise questions afterwards. I would recommend the following (you do not need to replicate books, one of each type is plenty!)

Extra ReadingElephants on Acid or Hippo Eats Dwarf

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