Descriptive Statistics Part 2 – Graphs

Teachers or students who want the original PPT please tweet @psychopepper

Learning Objectives

• To KNOW and UNDERSTAND what graphs are in psychology.
• To APPLY this knowledge of graphs to the grass head project.
• To ANALYSE the types of graphs in order to EVALUATE when to use them.

Lesson Outline:

Tasks:

1. To discuss the basics of graphs drawing, including titles, axis, colour and clarity.
2. To reflect on notes in booklet bar charts, histograms and line graphs.
3. To use data given in booklet in order to draw a bar chart, histogram and line graph.
4. To use data given in booklet to identify some common problems in data collection a graph drawing.
5. To assess graph drawing /15.
6. To choose a suitable graph and draw it for the grasshead project.
7. To attempt a past question on graph interpretation.

Content Recap:

Bar Chart: A bar graph is a chart that uses mostly vertical (although sometimes horizontal) bars to show comparisons among categories. It is because the data is on categories that the bar DO NOT TOUCH. the X axis of the chart shows the specific categories being compared, and the Y axis represents a discrete value/frequency. Bar charts are used for nominal data and some bar graphs present bars clustered in groups of more than one.

Histogram: A graphical display where the data is grouped into ranges (such as “40 to 49”, “50 to 59”, etc), and then plotted as bars. Similar to a Bar Graph, but in a Histogram each bar is for a range of data. It is because the data is in a continuous range that the bar DO TOUCH. the X axis of the chart shows the continuous measurement being used, and the Y axis represents the frequency. Histograms are used for ordinal data – where the data can be put into order smallest to largest.

Line Graph: A line chart or line graph is a type of chart which displays information as a series of data points called ‘markers’ connected by straight line segments.. Similar to a histogram, the X axis of the chart shows the continuous measurement being used, and the Y axis represents the frequency. Again similar to histograms, line graphs are used for ordinal data – where the data can be put into order smallest to largest. However they also allow us to plot more that one condition on top of one another for comparison.

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

TEXTBOOKS OR EXTRA READING:

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!)

• Complete Companion Series:
  • Textbooks affectionately known as catbook (Year 1) dogbook (Year 2).
  • Revision Guides affectionately known as kittenbook (Year 1) puppybook (Year 2).
  • Exam Companions also affectionately known as kittenbook (Year 1) puppybook (Year 2).
  • Research Methods guide
• Psychology for A Level:
  • Textbooks affectionately known as green hair girl (Year 1) pink hair girl (Year 2)
  • Revision Guides affectionately known as green hair girl (Year 1) pink hair girl (Year 2)
• CGP
  • Maths for Psychologists

Extra Reading – Elephants on Acid or Hippo Eats Dwarf