PSYCHOLOGY IA THE RESULTS

RATIONALE/PURPOSE The results section is where you report the results that you have found from your experiment. The results section is where you report the results that you have found from your experiment. You must report exactly what you found, however you must not explain why you found it here, this goes in the discussion. You must report exactly what you found, however you must not explain why you found it here, this goes in the discussion.

ASSESSMENT CRITERIA HL Criterion E - 2 marks HL Criterion E - 2 marks Results are clearly stated and accurate and reflect the hypotheses and research. Appropriate descriptive statistics are applied to the data and their use is explained. The graph of results is accurate, clear and directly relevant to the study. Results are presented in both words and tabular form.

HL Criterion F – 3 marks An appropriate inferential statistics test has been chosen and explicitly justified. Results of the inferential statistical test are accurately stated. The null hypothesis has been accepted or rejected appropriately according to the results of the statistical test. A statement of statistical significance is appropriate and clear.

THE ESSENTIALS The essential elements of your results section are as follows: The essential elements of your results section are as follows: Descriptive statistics (justification of and explanation of) Descriptive statistics (justification of and explanation of) The results table (of descriptive statistics) The results table (of descriptive statistics) Graph (of descriptive statistics) Graph (of descriptive statistics) Inferential statistics (justification of and interpretation of) Inferential statistics (justification of and interpretation of)

DESCRIPTIVE STATISTICS Your project must contain two forms of descriptive statistics Your project must contain two forms of descriptive statistics 1) measures of central tendency 1) measures of central tendency - (i.e. mean/ median/ mode) 2) measure of dispersion 2) measure of dispersion - (i.e. standard deviation)

MEASURES OF CENTRAL TENDENCY This includes the mean, median and mode. This includes the mean, median and mode. You must first of all justify why you have chosen to use the mean, median or mode, i.e. what are the strengths and weaknesses of them? Which is the most appropriate? Why? You must first of all justify why you have chosen to use the mean, median or mode, i.e. what are the strengths and weaknesses of them? Which is the most appropriate? Why?

MEASURES OF CENTRAL TENDENCY Then, you must include a table of the calculated values of mean, median or mode. Then, you must include a table of the calculated values of mean, median or mode. Do NOT include your workings out here, they go in the appendix (see ‘additional important resources’). You can use a calculator. Do NOT include your workings out here, they go in the appendix (see ‘additional important resources’). You can use a calculator.

MEASURES OF CENTRAL TENDENCY Then, you must explain what the calculated values show. This must be detailed, i.e. Use actual data in your description. Are there any obvious outliers in the results table which may have distorted the mean? Etc.

MEASURE OF DISPERSION The appropriate measure of dispersion for interval/ratio data is the standard deviation. This shows how spread out the data are from the mean. The appropriate measure of dispersion for interval/ratio data is the standard deviation. This shows how spread out the data are from the mean. You must first justify why you have chosen this. Hint! Look in the Course Companion p398 for the conditions under which the SD is used. You must first justify why you have chosen this. Hint! Look in the Course Companion p398 for the conditions under which the SD is used.

MEASURE OF DISPERSION Then, you must include the calculated value of the standard deviation for conditions A and B in a table. Put it in the same table as you did for Mean/median or mode. Then, you must include the calculated value of the standard deviation for conditions A and B in a table. Put it in the same table as you did for Mean/median or mode. Do NOT include your workings out here, they go in the appendix You can use a calculator or excel. Do NOT include your workings out here, they go in the appendix You can use a calculator or excel.

MEASURE OF DISPERSION Then, you must explain what the calculated value shows. Then, you must explain what the calculated value shows. This must be detailed, i.e. Which SD is larger? What does this mean? This must be detailed, i.e. Which SD is larger? What does this mean?

THE RESULTS TABLE You must include a table of results. Not raw data, this goes in the appendices. You must include a table of results. Not raw data, this goes in the appendices. Make sure you give a clear and detailed title. Make sure you give a clear and detailed title.

GRAPH You must display your results in an appropriate graph. Only one graph is required. You must display your results in an appropriate graph. Only one graph is required. Make sure you give a clear and detailed title. Make sure you give a clear and detailed title. Label axes correctly Label axes correctly

INFERENTIAL STATISTICS The appropriate measure of statistical significance depends on: The appropriate measure of statistical significance depends on: 1) Test of difference or correlation 1) Test of difference or correlation 2) Level of data 2) Level of data 3) Whether the data is related (repeated measures) or unrelated (independent measures) 3) Whether the data is related (repeated measures) or unrelated (independent measures) It will either be a Wilcoxon signed ranks test (repeated measures) or a Mann Whitney U test (independent measures) depending on whether you have used repeated measures or independent groups respectively. It will either be a Wilcoxon signed ranks test (repeated measures) or a Mann Whitney U test (independent measures) depending on whether you have used repeated measures or independent groups respectively.

INFERENTIAL STATISTICS You must first justify why you have chosen your statistical test. You must first justify why you have chosen your statistical test. You need to explain the conditions under which the test is used (Hint! This is explained on the previous slide!). Data is at least at the ordinal level. You need to explain the conditions under which the test is used (Hint! This is explained on the previous slide!). Data is at least at the ordinal level. Working out can be done on the computer but a printout must be provided. See booklet for more detailed instructions. Working out can be done on the computer but a printout must be provided. See booklet for more detailed instructions.

INFERENTIAL STATISTICS There are different levels of significance. There are different levels of significance. The p<0.05 level is used as it is the conventional level of significance that is accepted by psychologists. The p<0.05 level is used as it is the conventional level of significance that is accepted by psychologists. P<0.05 means that there is a 95% chance that the results occur due to an effect of the IV on the DV, and a 5% chance that the results occur due to random variability. P<0.05 means that there is a 95% chance that the results occur due to an effect of the IV on the DV, and a 5% chance that the results occur due to random variability. The ‘p’ stands for ‘probability’ The ‘p’ stands for ‘probability’

INFERENTIAL STATISTICS You must then interpret your stats test results using a ‘numerical statement of results’. This should include: You must then interpret your stats test results using a ‘numerical statement of results’. This should include: Calculated value (T (wilcoxon) OR U (Mann Whitney) Calculated value (T (wilcoxon) OR U (Mann Whitney) Critical value Critical value No. of Participants (N) No. of Participants (N) One tailed hypothesis One tailed hypothesis Level of significance Level of significance Whether the null hypothesis is retained or rejected. Whether the null hypothesis is retained or rejected.

NUMERICAL STATEMENT OF RESULTS EXAMPLE The calculated value from the Wilcoxon/Mann Whitney test was __. This is less than/ more than the critical value of __ for a directional/ non-directional (1 tailed/ 2 tailed) hypothesis when N = __. This shows that the risk that this difference occurred by chance is more than/ less than 0.05 or 5%. The result is therefore significant/ non-significant and the null hypothesis can be rejected/ retained.