Correlation

• What are the three types of correlation?

  Positive, negative, and zero correlation.
• What is positive correlation?

  Positive correlation is when the value of one variable increases so does the other or both values can also decrease at the same time
• What is negative correlation?

  Negative correlation is when the value of one variable increases, the other decreases
• What does zero correlation mean?

  Zero correlation is when there is absolutely no relationship between variables
• What is correlation?

  Correlation involves at least two variables to establish wether there is a relationship between them.
• Association between variables measured by correlation does not infer cause and effect
• what is an advantage of correlation?

  P: they can identify possible relationships that can lead to further avenues of study (e.g. further lab experiments)

  Example: aggressive parents raising aggressive children. conduct an experiment on different parenting style to advise parents how to raise children non-aggressively

  C: this is a strength because the correlation could lead to practical applications that could benefit society.
• What is a disadvantage of correlation?

  P: only examines the strength of a relationship, not cause and effect

  Example: higher cases of drowning as temperature increases

  other factors: alcohol consumption, swimming ability

  C: this can lead to inaccurate conclusions being drawn resulting in research being low in validity and accuracy as other factors may be involved
• correlational hypothesis for correlation

  One tailed: there will be a significant positive/negative relationship between…

  Two tailed: there will be a significant relationship between…

  Null: there will be no significant relationship between… any relationship will be due to chance
• For a correlational hypothesis, never write the words ‘difference’ or ‘effect’ as we are investigating the relationship not how the variables affect eachother.
• What is a benefit of using scatter graphs to represent data?

  You can eyeball the results as you can see at s glance wether data is moving in the positive or negative direction or if there is no direction at all
• What was our group practical for correlation?

  To investigate if there is a relationship between height (cm) and confidence (on a rating scale of 1-10)
• what sampling method did we use for our correlation practical? describe your sample

  we used opportunity sampling: people who are freely and readily available

  sample: 20 participants, mixed gender, 16-17 years of age, year 1 A-level students
• Conducting our correlational experiment - must be replicable (where, when, what and how)

  Where: in a psychology classroom

  When: e.g. Tuesday morning

  What and how: height (V1) was operationalised by measuring in cm and confidence levels (V2) was operationalised by using a rating scale of 1-10 (1= not confident, 10= extremely)

  We gathered scores for V2 by having everyone write a number (1-10) on a post it note and then write their height on the post it note after they got measured
• what were some BPS ethical guidelines to consider during our correlation practical?

  • confidentiality as post it notes were anonymous and height and confidence levels were kept confidential
  • Informed consent because all students agreed to rate their own confidence and have their height measured in cm
  • All participants also had the right to withdraw
  • Debrief as all participants were thanked and anyone with low confidence levels were offered counselling and given leaflets
• what was one control over EV’s in our correlation practical?

  • height measured in cm for every single participant
  • the same rating scale was used to measure confidence (1= not confident, 10= extremely)