1. Correlations Psychological Investigations

2. Suzie’s goldfish lives in a tank on her desk. The more fizzy drinks she consumes, the more her fish swims around. Can we say there is cause and effect? Goldfish and Fizzy Drinks..

3. Content Page SLIDES 1. Describe & Evaluate the Method 2. Hypothesis & Variables 3. Design n/a 4. Sampling Method n/a 5. Operationalisation & Measurement n/a 6. Reliability & Validity of measurement 7. Ethical Issues 8. Data (Graphical & Conclusions) 9. How would improve…? 10. Writing a Procedure

4. 1. Description & Evaluation Correlations

5. What is a correlation?

6. Strengths and Weaknesses

7. Age affects a child’s ability to understand that volume stays the same even when shape changes. The duration of eye movements in sleep are related to the perceived the length of a dream. There is a link between the size of the hippocampus in the brain and a person’s navigational ability. Children are more likely to copy the behaviour of the same-sex adults than that of opposite-sex adults. Relationship or Cause and Effect 1.Using clues within the sentences identify if it is a relationship or cause and effect relationship. 2.Underline the two variables within each statement. EXT: If it is a relationship, what might be the third variable?

8. Types Positive is the relationship between two variables such that an increase in one accompanies an increase in another. For example: There is a positive correlation between students who revise more and high levels of achievement. Negative is the relationship between two variables such that an increase in one accompanies a decrease in another. For example: There is a negative correlation between the more you drive at night the less nervous you will be when you drive at night. No Correlation is when there is no relationship between variables

9. 1. The less aggressive a child is, the less physical force her parents are likely to use in disciplining her. The hotter the weather, the more crimes against people (mugging etc) tend to occur. The more you practice guitar playing, the less mistakes you make. The higher a male monkey’s testosterone level, the more aggressive he is likely to be. Are the following correlations positive or negative? EXT: Write your own positive and negative correlation.

10. 2. Hypothesis Correlations

11. Non Experimental Hypothesis Definition A statement of the relationship between the two co-variables Reasons for using An alternative to the null hypothesis (accept/reject)

12. Null Hypothesis Definition An assumption that there is no relationship in the population from which a sample is taken with respect to the variables being studied.

13. Hypotheses for correlations are slightly different as they predict a relationship between 2 variables rather than a difference caused by an IV. This is a one-tailed hypothesis as the hypothesis predicts the expected direction of results. A two-tailed hypothesis which does not predict the expected direction would be ‘there will be a significant correlation between the size of a child’s feet and their score on a maths test. There also needs to be a null hypothesis. They must be operationalised: to make the variables measurable Hypotheses for correlations

14. You want to see if there is a correlation between children's show size and academic ability. There will be a significant positive correlation between the size of a child’s feet,measured in cm’s and their % score on a 10 question maths test. There will be a significant correlation between the size of a child’s feet,measured in cm’s and their % score on a 10 question maths test. There will no significant correlation between the size of a child’s feet,measured in cm’s and their % score on a 10 question maths test.

15. Write an operationalised correlational hypothesis and a null hypothesis for an investigation into cognitive ability and alertness Correlational Hypothesis: Null Hypothesis: Hypotheses for correlations

16. Write an operationalised correlational hypothesis and a null hypothesis for an investigation into amount of sunshine and ice-creams sold Correlational Hypothesis: Null Hypothesis: Hypotheses for correlations

17. Let’s go back to the correlation we conducted last lesson and construct a: One tailed hypothesis Two tailed hypothesis Null hypothesis

18. 2. How strong the relationship is. What is a correlation coefficient? * This is a measure of the strength of the correlation. Correlation coefficient can be calculated in a number of ways such as with a Spearman Rho. This is one of the statistical tests that you need to know about at A2. If your design is a correlation, you always choose to use Spearman Rho as your statistical test. * The closer the coefficient is to 1 or -1 the stronger the correlation Perfect strong moderate weak no relationship - 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 +1 What can correlations tell us besides that there is a relationship?

19. 6. Reliability & Validity of Measurement

20. Evaluate/Assess How could you assess How could you improve

21. Reliability: Consistency Internal Reliability Split-half method (questionnaire) Inter-rater )observation External Reliability Test-Retest (questionnaire)

22. Validity: The legitimacy of a study Internal Validity Demand Characteristics: Features of an experiment the elicit a particular response form participants. Confounding variables affects the outcome of an investigation because it acts as an additional IV. External Validity Ecological validity: generalise from one setting to another Population validity: generalise from one group of people to everyone

23. 5. Validity of Measurement Concurrent (pre- established Criterion (different method)

24. 6. Ethical Issues  Deception  Informed consent  Psychological harm  Informed consent  Difficulty debriefing  Privacy  Confidentiality

25. 7. Data

26. 2. How strong the relationship is. What is a correlation coefficient? * This is a measure of the strength of the correlation. Correlation coefficient can be calculated in a number of ways such as with a Spearman Rho. This is one of the statistical tests that you need to know about at A2. If your design is a correlation, you always choose to use Spearman Rho as your statistical test. * The closer the coefficient is to 1 or -1 the stronger the correlation Perfect strong moderate weak no relationship - 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 +1 What can correlations tell us besides that there is a relationship?

27. Correlational analysis always involves quantitative data. When carrying out correlational analysis the data is summarised by presenting the data in a scattergram (or scattergraph). A scattergraph is a graph that shows the correlation between two sets of data (or co-variables) by plotting dots to represent each pair of scores. For each individual we obtain a score for each co-variable. It is important that the scattergram has a title and both axes are labelled. From the scattergram we may be able to say whether there is a strong positive correlation, a weak positive correlation, no correlation, a weak negative correlation or a strong negative correlation but we can not make a conclusion about the hypothesis. Scatter Graphs

28. Parts of a Scatter graph

29. Draw scatter graphs for the following: Positive correlation Negative correlation No correlation Scatter Graphs

30. How do the following Scatter graphs look? +1 Correlation 0.5 Correlation

31. Today we are going to test out whether there is a relationship between the number of hours you sleep and the amount of energy you have. Before we start what are the key words in the above statement? Let’s try one…. EXT: What type of correlation would you expect?

32. Participant# of sleep# of Star Jumps you can complete 1 2 3 4 5 6 7 8 How to Record the Data?

33. Let’s Display our Data

34. 8. How would you improve Validity Reliability Ethics

35. 9. Writing a procedure June 2013 Psychologists are interested in investigating if there is a correlation between age and ability to use the internet. Describe and evaluate a way to measure ‘ability to use the internet’ that could be used in this study. (10)