Correlations And Meta Analysis

Question 1

What is a correlation

Answer 1

• a correlation illustrates the Strength and direction of an association between two or more co-variables (things that are being measured)
• correlations are plotted on a scattergram
• one co-variable forms the X axis and the other the y-axis
• each point on the graph is the x and y position or each co-variable

Question 2

What is a positive correlation

Answer 2

One co-variable increases as the other increases (but not necessarily at the same rate) e.g. calories consumed and weight gained

Question 3

What is a negative correlation

Answer 3

One co-variable increases while the other co-variable decreases (but not necessarily at the same rate) e.g. hours spent sitting down and level of fitness

Question 4

What does it mean if there is zero correlation

Answer 4

There is no relationship between the co-variables e.g. hair colour and IQ

Question 5

Evaluation of correlations

Answer 5

✅ the data may be easily available for researchers to quickly analyse
✅ Correlations allow researchers to make predictions as to the relationship between co-variables
❌ Extraneous factors connected to one or both co-variables may affect the result and lead to invalid conclusions being made
❌ less successful when dealing with non-linear relationships, this limits the type of data that can be analysed and conclusion drawn

Question 6

What is the difference between correlations and experiments

Answer 6

• in an experiment the researcher controls or manipulates the independent variable in order to measure the effect of the dependent variable
• As a result of this deliberate change it is possible to infer that the IV caused any observed changes
• However in a correlation, there is no manipulation of one varable and therefore it is not possible to establish cause and effect between one co variable and another
• even if we found a strong positive correlation between caffeine and anxiety levels we cannol assume caffeine was the cause of the anxiety
• there are other reasons people may be anxious - these other variables are known as intervening variables

Question 7

What is a meta analysis

Answer 7

• A meta-analysis is a quantitative research method which takes data from published studies, other researchers have conducted the research and published the results e.g. a meta-analysis of 32 cross-cultural replications of the Strange Situation
• A meta-analysis procedure involves a statistical calculation of the numerical findings of lab experiments, correlational studies and questionnaire-based research
• The meta-analysis may use data from only one method e.g. lab experiments or from more than one method
• Researchers combine the findings from these multiple studies to draw an overall conclusion about the topic
• A meta-analysis allows for trends/patterns to be identified by combining the data of lots of smaller studies

Question 8

Evaluation of meta analysis

Answer 8

✅ there is less chance of bias confounding the results due to the use of secondary data as researchers have not carried out the research themselves so they cannot have influenced the outcome in any way, this increases the reliability of the findings as a large number of studies analysed statistically increases the robustness of data (known as statistical power)
✅ It is possible to generalise the findings to a wider population due to the number of studies included in the meta-analysis
❌ The use of secondary data means that the researchers cannot be 100% confident as to the degree of precision exercised by the original researchers
❌ It may be difficult for the researcher to access relevant studies