Answers to Olsson HW

  1.  IV and DV

IV: Whether the Pp sees a purple leaf or any other the other images, e.g. green leaf, blue moon, a red square, a yellow submarine

DV: the participants galvanic skin response measured in micro-Siemens (μS)

2. State a suitable directional hypothesis for this study (3)

People who have observed another adult being shocked when they see a purple leaf (but not when they see other coloured shapes) will display a higher galvanic skin response (in microsiemens) when they are shown purple leaves compared with other coloured shapes.

3. State the experimental design used in this study (1)

Repeated measures

4. What is the level of measurement of the data in this study (1)


5. Construct a summary table to show the means and standard deviations for Helena’s data (4)

Mean Standard deviation
Purple leaf 29.5 7.76
Green leaf 27.125


6. Draw a bar chart to illustrate Helena’s data (5)

Make sure it has full title, full labelling of axes with units, bars must not touch, gap between y axis and first bar.

7. Which stats test should Helena use and why? (4)

Repeated measures and at least ordinal data looking for test of difference so….Wilcoxons.

8. Conduct the appropriate stats test (4)

9. Explain whether Helena should accept or reject her null hypothesis. You will need to use the critical values tables from the front of an exam paper. (4)

10. Describe any experimental controls that you think Helena would have put in place to preserve the internal validity of her conclusions.

  • She should have made sure that all Pps were in the exact same environment with factors such as sounds and lighting controlled which could have otherwise affected the GSR.
  • She should also have made sure that all the Pps were exposed to the same film of the elderly person being shocked  for the same amount of time.
  • Make sure they use the same GSR monitor to get reliable measurements.

12. Evaluate Helena’s study with reference to generalisability, reliability, validity, ethics and practical applications to real life. (20) This is a band marked applied exam question with the command term “Evaluate”.