Psychology Life Hack of the Week Might there be a point in palmistry? Research shows that the ratio of index finger to ring finger is associated with a variety of behaviours and personality traits, e.g. low digit ratio (below 0.95 in males and 0.97 in females) is linked to increased assertiveness whereas above average ratios are associated with greater verbal fluency.

Be prepared to feedback about both the question and your answer. Another group have sent you postcards. Your job is to answer their questions. Be prepared to feedback about both the question and your answer.

BAAM!

You will have a short test on experimental research methods in next week’s lesson.

Descriptive vs Inferential Statistics Descriptive Statistics Organise Summarise Simplify Present data Inferential Statistics Make inferences Generalise from samples to populations Hypothesis testing Make predictions

Inferential Statistics, Significance and Probability Read the notes on page 2 and answer the following questions: 1. Why do we use inferential statistics? To see whether a finding is significant or due to chance factors. 2. What is meant by the ‘significance level’? The ‘level of proof’ required to accept/reject the null hypothesis. 3. Explain what p ≤ 0.05 means. There is a less than (or equal to) 5% probability that a finding was due to chance. 4. When would the p ≤ 0.01 level be used? When stronger evidence is needed, e.g. drug trials

The Sign Test The hypothesis predicts a difference. The experimental design is related (repeated measures). The data is nominal (categories).

Subtract second column from first: Record ‘-’, ‘+’ or omit results if same. Add up the plus and minus signs. Take the less frequent sign as the value of S. Here, S = 2 Page 3

Level of significance for a one-tailed test. 4. Compare the calculated value of S with the critical value on the table. Level of significance for a one-tailed test. N = number of scores minus those that scored the same in both conditions. N = 8 (10-2) The calculated value must be less than/equal to the critical value for significance. Page 4

5. Complete the following statement. Conclusion: We can see from the investigation that the calculated value of S=2 is more than the critical value of 1 where N = 8. Therefore the difference is not significant at the accepted P < 0.05 level. Therefore the researcher should accept the null hypothesis that: There will be no difference in the test scores of students when they eat breakfast as compared to when they have not eaten breakfast.   [If the result is significant add the following:] This means we can accept the research hypothesis that: Page 5

Page 5 Calculate the value of S. Show your workings.   Calculate the value of S. Show your workings. Is the result significant? Explain your answer. What can the researcher conclude about the new Fizz-Buzz cereal? Page 5

  Calculate the value of S. Show your workings. Is the result significant? Explain your answer. What can the researcher conclude about the new Fizz-Buzz cereal? S= 1 (as there is 1 ‘-’, the least frequent sign, 7 ‘+’ and 2 omitted scores ) The calculated value of S = 1 is more than the critical value of 0 where N = 8 (two-tailed test). Therefore the difference is not significant at the p ≤ 0.05 level. They can accept the null hypothesis that there will be no significant difference in the number of people expressing a preference for Kiddy Slop and Fizz-Buzz.

Exam Question In pairs/threes, read the stem and answer the questions: The psychologist obtained the following results: • For two of the prisoners the number of aggressive acts increased • For eight of the prisoners the number of aggressive acts decreased • For two of the prisoners the number of aggressive acts stayed the same What is the calculated value of S? Explain your answer. [2 marks] Using the table of critical values, state whether the findings are significant at p < 0.05. Explain your answer. [2 marks]

Mark the Answer Swap answers and use the criteria below.

I am a researcher interested in memory. On the following page is a list of words. You will be given 30 seconds to read the words. You will then be asked to write down as many words from the list as you can remember. You will have one minute to complete this task.

Love Tractor Sandwich Robot Frame Phone Front Gum Tunes Orange Juice Cottage Rewind Mirror Trivia Handle Level Dog Young Plane Drop

Please write down as many words from the list as you can remember. On the next slide is another list of words. You will have 30 seconds to read the words. You will then be asked to write down as many words from the list as you can remember. You will have one minute to complete this task.

Bien Etat Cela Requin Dans Livres Autres Rouge Aussi Temps Samedi Avant Beacoup Deux Moutons Frein Entre Euro Chien Perdu

Thank you for taking part in the study. Please write down as many words from the list as you can remember. Thank you for taking part in the study.

Let’s record your results – page 7 Participant No. English Words (A) French Words (B) A-B Direction of difference 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Review Your Knowledge – page 6-8 Complete the details of this mini-practical (IV, DV, hypothesis, etc.) Use the table of results to calculate the value of S. Explain your working. Using the table of critical values, explain whether the findings of the study are significant at the p ≤ 0.05 level. Draw a suitable graphical display to present the data. Answer the question about standardised instructions and procedures. Finished? Complete the exam practice question on the sign test (page 8)

Develop a resource (e.g. a crossword or quiz) to test another student’s knowledge Review the evaluations for types of experiments, designs, sampling techniques and descriptive stats. Assess your leaning of each of our topics so far – make a note of anything you need to work on. Apply your knowledge – search for and answer exam questions on experimental research methods. Use the ‘Questions to guide your thinking …’ on each handout to check your learning Review the key terms/definitions of research methods so far.

Plenary: ‘The Pit’ of Research Methods 1. Indicate where you are with research methods in general. 2. Answer the questions on the reverse. Don’t forget to add your name!!!