Question 1: Explain the purpose of using inferential statistics in psychological research.

Answer: Inferential statistics are used to determine whether the results observed in a sample can be generalized to the larger population, helping researchers decide if findings are statistically significant.

Question 2: A psychologist conducts an experiment and finds a p-value of 0.03. What does this p-value indicate about the results?

Answer: A p-value of 0.03 suggests that there is a 3% probability that the results occurred by chance. Since it is below the common significance level of 0.05, the results are considered statistically significant.

Question 3: Describe the difference between a null hypothesis and an alternative hypothesis in psychological research.

Answer: The null hypothesis states that there is no effect or difference between variables, while the alternative hypothesis suggests that there is a real effect or difference. Inferential statistics test these hypotheses.

Question 4: A researcher compares scores from two different groups using a t-test. What does a significant t-test result tell us?

Answer: A significant t-test result indicates that there is a statistically significant difference between the two groups, unlikely due to chance.

Question 5: Explain what is meant by 'confidence interval' in the context of psychological research.

Answer: A confidence interval is a range of values around a sample statistic that is likely to contain the true population parameter, usually expressed with a confidence level such as 95%.

Question 6: A psychologist reports a correlation coefficient of 0.8 between two variables. What does this tell us about the relationship?

Answer: A correlation coefficient of 0.8 indicates a strong positive relationship between the two variables, meaning as one increases, the other tends to increase as well.

Question 7: Describe the purpose of a chi-square test in psychological research.

Answer: A chi-square test is used to determine whether there is a significant association between categorical variables, such as different groups or categories.

Question 8: Draw a simple graph that could be used to display the results of an experiment comparing two conditions with a clear difference. Label the axes and legend.

Answer: A bar graph with two bars, one for each condition. The x-axis labeled 'Conditions' with categories 'Condition A' and 'Condition B'. The y-axis labeled 'Average Score' or 'Frequency'. The bars should show a noticeable difference in height.

Question 9: Why is it important to set a significance level (e.g., 0.05) before conducting statistical tests?

Answer: Setting a significance level before testing helps determine the threshold for deciding whether results are statistically significant, reducing the risk of false positives.

Question 10: A study reports an effect size of 0.2. How would you interpret this effect size in psychological terms?

Answer: An effect size of 0.2 is considered small, indicating a modest relationship or difference between variables in the study.