Unit 1 - Correlation

Question 1

What is a correlation

Answer 1

-shows a relationship between two co-variables

Question 2

what is a positive correlation

Answer 2

-This is where one variable increases and the other variable also increases
-E.g. you would expect to see a positive relationship between height and arm length

Question 3

what is a negative correlation

Answer 3

-This is where one variable increases and the other variable decreases
-E.g. you would expect a negative relationship between the number of maths lessons missed and scores on a maths test

Question 4

what is no correlation

Answer 4

-This is where there is no link between the two co-variables
-E.g. you would not expect to see any relationship between how many keys you own and your score on an IQ test

Question 5

what is the difference between correlation research and experiments

Answer 5

correlation research:
-Have co-variables
-Do not have a control group
-Look for a correlation or relationship, not a difference
-Can only use ordinal or interval/ratio level data (not nominal)
-Use scatter graphs only

experiments:
-Have IVs and DVs
-Have control groups and experimental groups
-Looks for an ‘effect’ or ‘difference’
-Can use any level of data
-Usually Bar charts or Pie charts

Question 6

what are research aims and research questions

Answer 6

research aims = is a statement about the purpose of the study E.g. To investigate if sunny weather is related to happiness
research questions= is a question related to what you are interested in finding out (must have a question mark)
E.g. Are people happier when it is sunny?

Question 7

how to operationalise co variables

Answer 7

-any co variables needs to be expressed as a number
-each participant must have two separate (ordinal level) numbers that relate to them - one for each co variable

Question 8

what will a null hypothesis and alternative hypothesis be in a correlation study

Answer 8

null= There will be NO SIGNIFICANT RELATIONSHIP between hair length and friendliness
alternative = There will be A SIGNIFICANT RELATIONSHIP between hair length and friendliness

Question 9

what will a two tailed and one tailed hypothesis be in a correlation study

Answer 9

One tailed =Predicts there will be a relationship and which direction it will go in
E.g. There will be a significant POSITIVE /NEGATIVE correlation between temperature and ice cream sales
Two tailed= Predicts there will be a relationship and but does NOT predict a direction
E.g. There will be a significant relationship between temperature and ice cream sales

Question 10

what is primary and secondary data

Answer 10

primary = collect data directly from the participants
secondary = data that has been gathered by someone other than the researcher

Question 11

factors that affect whether you use primary or secondary data

Answer 11

-Sampling method = Like with an experiment, you want the sample of participants (primary) or data (secondary) to be representative of the target population you are interested in.
-Ethics = if collecting primary data the researcher will need to obtain consent, avoid deceiving them, give them chance to withdraw etc. If using secondary data then it may be that this is already in public domain (not confidential)

Question 12

what are correlation coefficients and what do they show (relationship wise)

Answer 12

-1 - -0.8= strong negative correlation
-0.8 - -0.6 = moderate negative correlation
-0.6 - -0.4 = mild correlation
-0.2 - +0.2 weak to no correlation
+0.4 - +0.6 mild positive correlation
+0.6 - +0.8 moderate positive correlation
+0.8 - +1 strong positive correlation

if the correlation coefficient has a plus sign = positive correlation
negative sign = negative correlation
around zero = no correlation

Question 13

tips to remember when interpreting scatter graphs

Answer 13

-a scatter graph would never justify you in concluding that co variable X has had an EFFECT on co variable Y, you only find out whether there is a relationship
-a scatter graph would never justify you in saying that a particular hypothesis can be retained or rejected
-need to be careful not to confuse findings with conclusions (findings relate to raw data, conclusions relate to broad inferences that you can make from the data)

Question 14

what are the advantages and disadvantages of correlation studies

Answer 14

advantages:
-tell us about a relationship between co variables and the direction and strength of their relationship
-useful technique when either practical or ethical reasons mean that variables cannot be manipulated
-can be a good starting point for research

disadvantages:
-do not tell us anything about cause or effect
-the inferential statistics test will not always pick up on a relationship between two co variables
-don’t require the collection of any qualitative data= limits our ability to explain any relationship that might be found