1. Exam question 15 minutes to look over plan. 30 minutes to answer question Describe and evaluate the gender schema theory of gender development (8 marks + 16 marks)

2. Research methods

3. Recap: Levels of measurement most appropriate descriptive statistic to calculate which graph to use which inferential test to use Levels of measurement relate to quantitative data.

4. Levels of measurement: fill in the blank spaces ______ data: when the data is measured on a_____, like someone’s height or the number of items remembered in a memory test. _______data: the data is in some kind of ______ (order), for instance the _____that horses finish in a race ______ data: data that is in ________; if it is in one _______, it cannot be in another.

5. Levels of measurement: fill in the blank spaces Interval data: when the data is measured on a scale, like someone’s height or the number of items remembered in a memory test. Ordinal data: the data is in some kind of rank (order), for instance the order that horses finish in a race Nominal data: data that is in categories; if it is in one category, it cannot be in another.

6. Identify whether the data in each statement is nominal, ordinal or interval. 1.A psychologist counts the number of males and females who are shopping on a Saturday morning in Churchill Square. 2.A researcher measures how quickly participants can run 50 metres. 3.A researcher measures the temperature at which people feel most aggressive. 4.In a company participants were asked to indicate on a scale of 1-7 how much they felt in control of their working environment. 5.A researcher asks five year olds what their favourite flavours of ice cream are. 6.A psychologist measures the attachment style of children: secure or insecure. 7.A researcher asks participants to put ten photographs of faces in order from most to least attractive.

7. 1.A psychologist counts the number of males and females who are shopping on a Saturday morning in Churchill Square. nominal 2.A researcher measures how quickly participants can run 50 metres. interval 3.A researcher measures the temperature at which people feel most aggressive. interval 4.In a company participants were asked to indicate on a scale of 1-7 how much they felt in control of their working environment. Ordinal 5.A researcher asks five year olds what their favourite flavours of ice cream are. Nominal 6.A psychologist measures the attachment style of children: secure or insecure. Nominal 7.A researcher asks participants to put ten photographs of faces in order from most to least attractive. ordinal

8. Moving on to: Why we use inferential statistics Hypothesis Probability Levels of significance.

9. Why not just use descriptive stats? Descriptive statistics give us convenient and easily understood summaries of the data but we can’t draw any firm conclusions from them, they are just an overview. In order to draw firmer conclusions and to accept or reject hypotheses, inferential statistics are needed.

10. What is a hypothesis? Two hypothesis are formulated at the beginning of a study: The alternative hypothesis (H1) – Predicts that there will be a significant difference – Directional or non directional The null hypothesis (HO) – predicts that there will not be a significant difference

11. What is a null hypothesis and why do we need one? The null hypothesis predicts that any difference between two or more sets of data will have occurred through chance alone If it is rejected then we must retain the alternative hypothesis and vica versa. If the null hypothesis is rejected we say our results are statistically significant. If it is accepted we say they are NOT significant. We focus on the null hypothesis because it eliminates bias from the research by forcing the researcher to consider the view that any difference found between the two sets of data has occurred through chance alone

12. A team of psychologists was interested in studying the effects of alcohol on peoples' reaction times. Earlier research suggested that an increase in reaction time was due to the alcohol rather than peoples' expectations of alcohol. The psychologists recruited two groups of volunteers (an independent groups design) from a local university. Each participant's reaction time was measured by using a computer game. The participants were then given a drink. The first group received a drink containing a large measure of strong alcohol; the second group received an identical drink without alcohol, but with a strong alcoholic smell. Finally, all participants were required to play the computer game again to assess their reaction time. Once they had completed the task, they were then thanked for their time and allowed to leave. What is the IV? whether the participants have had an alcoholic drink or one that is not alcoholic but smells as if it is What is the DV? reaction times on a computer game Null hypothesis: There will be no difference between the university students‘ reaction times on a computer game between those who have had an alcoholic drink or one that is not alcoholic but smells as if it contains alcohol; any differences are due to chance factors.

13. A teacher in a small secondary school wanted to find out whether there was any truth in her idea that students who used a computer regularly for their homework achieved higher exam grades than those who did not. She decided to interview a sample of 30 students taken from across the school. She tape-recorded all the interviews. She later obtained their end of year exam grades from their reports. What is the IV? whether the participants used a computer regularly for their homework or didn’t use a computer regularly for their homework. What is the DV? Exam grade achieved Null hypothesis: There will be no difference between the exam grades achieved at the end of year between those who regularly used a computer to complete homework and those who did not regularly use a computer to complete homework; any differences are due to chance factors.

14. What is statistical significance then?! Inferential statistics is a test of significance because it is designed to assess whether we reject or retain the null hypothesis. If the null hypothesis is retained, the result is not significant; if it is rejected the result is significant. Inferential statistical tests work by assessing the probability of our results occurring due to chance alone (rather than the IV) We use it to determine if the probability of our results being down to chance is low enough for our alternative hypothesis to be accepted.

15. The inferential test ends with a probability value (p), which can be anything between 0 and 1. The value indicates the probability that the null hypothesis is true. Inferential statistics do not tell us that a null hypotheses can certainly be rejected, only the probability that it can be rejected. In order for psychologists to judge that they can reject the null hypotheses and retain the alternative hypotheses the probability value must be very small.

16. Probability and Significance Probability, or p, is expressed as a number between 0 and 1. 0 means an event will not happen. 1 means that an event will definitely happen. The P value will always be found to be between 0 and 1 due to the way in which it is calculated.

17. Activity To give you an idea and to keep things easy complete the following exercise using 0 – 100 rather than 0 - 1 On a scale of 0-100 rate the following statements for probability 0 = Impossible and 100 = Certain (Remember the only thing certain is death and the only thing impossible immortality!) You winning the lottery It raining in the next week Dreaming of elephants this week Having a day off ill this term Becoming a famous entertainer Becoming a parent in your lifetime A cure for cancer being discovered in your lifetime If you spin a coin it will come down heads If you spin two coins they will both come down heads Passing all you’re A levels

18. Because we used a scale between 0-100 your answers are expressed as percentages. Convert them into fractions and then decimals e.g. 50% is ½ or 0.5 (move the decimal point two places to the left. This converts the probability to a decimal between 0 and 1)

19. The aim of inferential statistics is to discover if your results are statistically significant. A statistically significant result is one which is unlikely to have occurred through chance. Levels of significance Researchers can use significance levels of 10%, 5%, 1% (or 0.1% in very stringent conditions) - expressed as: 10%, 0.10, 1 in 10, p≤0.10. 5%, 0.05, 1 in 20, p≤0.05 1%, 0.01, 1 in 100, p≤0.01 If you use a 5% statistical significance level and this is achieved you are saying that the probability of your results being a fluke and nothing to do with your IV is less than 5%. or you are 95% sure that your change in DV is because of your IV

20. We express our results in terms of the Null Hypothesis, if a result is statistically significant we can reject the null hypothesis. If the result is not statistically significant we must accept the null hypothesis. Null Hypothesis: - Any difference between the two conditions is due to chance.

21. Take a pack of cards… I want to judge whether there is… – ‘nothing funny’ going on with the cards (the null hypothesis) Or whether…. – “there is something funny going on “ – the research hypothesis.

22. Significance level I cardProbability is 50:50 that the card is red i.e. 0.5 50 % 2 cards 3 cards 4 cards 5 cards 6 cards What are the chances, if there was nothing going on? 22

23. Significance level I cardProbability is 50:50 that the card is red i.e. 0.5 50 % 2 cards 0.5 x 0.5 = 0.2525 % 3 cards 0.5 x 0.5 x 0.5 = 0.125About 12 % 4 cards 0.5 x 0.5 x 0.5 x 0.5 = 0.0625About 6 % 5 cards 0.5 x 0.5 x 0.5 x 0.5 x 0.5 = 0.03125About 3 % 6 cards 0.5 x 0.5 x 0.5 x 0.5 x 0.5 x 0.5 = 0.015625About 1 % 5 % level What are the chances, if there was nothing going on? 23

24. At what point do we judge that something funny is going on when the picked cards are all red? Probably on the 4 th card. The probability of the first 4 cards picked being red is 6%. So the probability of the null hypothesis being correct is less that 6%. This finding supports the alternative hypothesis: that the first 4 cards picked at random are NOT due to chance. Activity: complete task 8

25. Next lesson Type 1 and Type 2 error Choosing an appropriate statistical test