OxfordAQA International A Level Psychology 3.3.3 Research Methods 2 Exam Questions

About OxfordAQA International A Level Psychology 3.3.3 Research Methods 2

Research methods 2 is the third section of Unit 3 on the OxfordAQA International A2 Psychology course. It builds on Research methods 1 with further methods, content analysis and case studies, and a deeper treatment of reliability and validity. You learn the sections of a scientific report and referencing, and you move into inferential statistics: probability, significance, critical values, Type I and Type II errors, levels of measurement and choosing the right statistical test. Examiners usually present a novel study and ask you to choose and justify a test, interpret a result against a critical value and suggest how to improve reliability or validity.

What you need to know

• Content analysis and case studies Content analysis turns qualitative material, such as media, into quantitative data using coding categories. Case studies investigate one person, group or event in depth, often using several methods; they give rich data but are hard to generalise.
• Reliability Test-retest reliability gives the same test to the same people on two occasions and correlates the results. Inter-observer reliability compares the records of two or more observers; a correlation of about +0.8 or above is usually seen as acceptable.
• Validity Face validity is whether a measure appears to test what it claims. Concurrent validity compares results with an established measure; predictive validity checks whether scores predict future behaviour. Ecological validity is the extent findings generalise to real settings. Correlation can be used to assess concurrent and predictive validity.
• Reporting research A report has an abstract, introduction, method, results and discussion, followed by references in a standard format.
• Probability and errors The usual significance level in psychology is p ≤ 0.05. A Type I error is rejecting a true null hypothesis (a false positive), more likely with a lenient level such as 0.10. A Type II error is accepting a false null hypothesis (a false negative), more likely with a strict level such as 0.01.
• Choosing tests Choice depends on whether you test a difference or a correlation, whether the design is related or unrelated, and the level of measurement (nominal, ordinal or interval). Tests include the sign test, chi-squared, Wilcoxon, Mann-Whitney, Spearman's rho, Pearson's r and related and unrelated t-tests.

Common mistakes in 3.3.3 Research Methods 2

• Mixing up Type I and Type II errors. Type I is a false positive; Type II is a false negative.
• Forgetting to check whether the calculated value must be greater or less than the critical value for that test. For tests such as Mann-Whitney, Wilcoxon and the sign test, the calculated value must be equal to or less than the critical value.
• Choosing a test from the design alone. You must also consider the level of measurement and whether you are testing a difference or a relationship.
• Describing validity as 'how accurate a study is'. Name and explain the specific type of validity.
• Writing an abstract that only states the aim. An abstract summarises aims, method, results and conclusions.

Try three 3.3.3 Research Methods 2 exam-style questions