correlation

• what is a correlational study

  a method to investigate if there is a relationship between two continuous variables
• what types of variables are present in a correlation study

  co-variables (NOT DV AND IV)
• what two things can a correlation tell us

  the direction of the relationship and the degree of the relationship between two variables
• what is positive correlation

  when co-variables increase so does the other and has a correlation coefficient > 0 and < 1 - a positive value
• what is negative correlation

  as one co-variable increases the other decreases and has a correlation coefficient <0 and > 1 - a negative value
• what is zero correlation

  when there is no relationship between two variables and has a correlation coefficient of 0
• what is meant by the degree of the relationship

  an indication of how strongly two co-variables are related- the closer the correlation to 0 the weaker the correlation
• what is included in a scattergram

  include a title

  label each axis and include units

  the axes need to go up by a standard amount

  plot each points with a cross

  each cross represents one P
• what are the hypotheses for studies using the correlation method

  an alternate correlation hypotheses will predict that there is a relationship between the co-variables (this includes directional and non-directional)

  a null hypothesis will predict that there will be no relationship between the co-variables
• what are the key differences between experiments and correlation

  variables - IV and DV vs co-variables

  hypotheses- difference vs relationship

  graphs- bar chart/histogram vs scatter graph

  conclusions- cause and effect vs relationship
• what is a strength of the correlation method

  can be used when it is unethical or not practical to carry out an experiment- sometimes variables can't be manipulated- doing a correlation allows these variables to be examined together to see if there is a pattern-psychology can discipline further as a science as correlations help to further knowledge
• what is a strength of the correlational method

  collects quantitative data- numerical data is collected and can be plotted on a scatter graph- this type of data is more objective and can be checked by other researchers- statistical analysis can be performed and comparisons can be made between variables
• what is a strength of the correlational method

  very useful as a pilot study for an investigation- provide and indication of how two variables are related and may suggest ideas for future research- it is good to get a preliminary idea about whether it would be worth investing in studying this area
• what is a strength of the correlational method

  it can be carried out using pre existing data- there is no need for a controlled environment and no manipulation of variables is needed- it will be quick and economical to carry out a correlational method a secondary data can be used instead
• what is a drawback of the correlational method

  it cannot show cause and effect- it isn't knows if or which variable is having an effect on the other- this means that correlations only describe they do not explain why a pattern of results are occurring- this a problem for psychology as it defies the standards of a science
• what is a drawback of the correlational method

  there is a third variable problem-there may be another intervening variable which may be causing the behaviour- this is called an intervening variable and is essentially an extraneous variable- this would reduce the internal validity of the findings