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A2. How science works & Research methods. Timing and attack strategy. 2 hours in total Section A and B worth 48 marks Section C worth 35 marks. 70 mins 50 mins. Every mark counts. 6 marks is the difference between a grade. RM ab. The research methods specification.
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A2 How science works &Research methods
Timing and attack strategy • 2 hours in total • Section A and B worth 48 marks • Section C worth 35 marks 70 mins 50 mins Every mark counts. 6 marks is the difference between a grade.
RM ab The research methods specification
A good scientist is a skeptic. Science ≠ laboratory. Science is important. Knowledge vs belief.
The scientific process Observe behaviour around you Develop an explanation/hypothesis Produce a research prediction Conduct a study to test the prediction and get results Draw conclusions Refine the explanation/hypothesis Bibb Latané and John Darley
RM ab Validating new knowledge Scientists find out about each other’s work by reading journal articles. • Tends to reject papers that challenge conventional research. • Tends to reject replications. • Tends to favour well-known researchers. • Is anonymity better? Or worse? • Errors don’t get corrected. • Web publications. Abstract Introduction Method Results Discussion Conclusion The scientific process Peer review
RM ab The research methods specification
Exam FOCUS 3 marks
RM ab The research methods specificationCandidates will be expected to: Design investigations. Understand how to analyse and interpret data arising from such investigations. Report on practical investigations. In order to gain sufficient understanding … candidates will need to practise these skills by carrying out, analysing and reporting small-scale investigations.
Exam FOCUS Design it yourself Test a new idea: People notice the change when the person is the same age as them rather than a different age. • You have access to a sixth form of 200 students. • identify the design that you would use • explain an appropriate sampling method and justify your choice • describe the procedure that you would use, including details of how you would assess the DV • write a suitable debrief for these participants. What other questions?
RM ab The research methods specification
Probability and significance Null hypothesis There is nothing going on. Alternative hypothesis This is the fixed pack. There is something going on.
Probability and significance 5 % level
Probability and significance I keep seeing my best friend’s boyfriend around campus talking to this other girl He says nothing is going on If nothing is going on, how come he seems to always be with her? REJECT NULL HYPOTHESIS ACCEPT ALTERNATIVE What’s the likelihood of that if there is nothing going on? THERE IS SOMETHING GOING ON
RM ab Probability and significance • Research study • Group A does test with loud music • Group Bdoes test in silence There is nothing going on. There is no difference between test results from Group A and B. Null hypothesis? There is something going on. Test results from Group A and B are different. Alternative hypothesis? We do the study …
RM ab Probability and significance • What can you infer from these graphs? • There is something going on • There is nothing going on • Not sure
RM ab Inferential statistics
RM ab Levels of measurement Nominal names Ordinal ordered Interval equal intervals
RM ab Inferential statistics • Bandura’s Bobo study involved two groups of children, one group saw a violent model and the other group saw a non-violent model. Both groups were later rated for their aggressiveness in a play situation. • In a similar study, children were not rated but were simply classed as aggressive or not.
RM Determining significance Table of critical values for Spearman’s rho Observed value of rho must be equal or greater than the critical value in the table for significance to be shown) The observed (calculated) value of rho is 0.456 …. The hypothesis was directional. There were 15 participants. 5% level of significance. Is it significant?
RM Stating conclusions • Statement of results • As the observed value (0.456) • is greater than the critical value (0.443) • at p ≤ 0.05, • this means we can reject the null hypothesis • and conclude that …. [state the hypothesis]. The observed (calculated) value of rho is 0.456 …. The critical value (p ≤ 0.05) is 0.443. It is significant.
Type 1 and Type 2 errors If you were on a jury which mistake would you avoid? • Convicting an innocent man (Type 1 error). • Letting a guilty man go free? (Type 2 error) Null hypothesis: This man is not guilty i.e. innocent.
Which way would you lean? • Null hypothesis: This person is not ill i.e. is healthy. There is nothing going on.
Type 1 and 2 errors happen when a hypothesis is mistakenly rejected. Type I error H0 is rejected when it is in fact true. Type 2 error H0 accepted when it is false. Type 1 error happens when we set the bar too high.
Qualitative research One significant indication of schizophrenia was my inability to plan my future. I took courses in University that sounded interesting with no real plan. I was notably incapable of developing another long term romantic relationships and in fact was very anxious in any kind of social situation. At graduate school I kept going to the university clinic about my physical health, afraid that my health was going to fall apart. I thought the town water supply had become contaminated because it tasted metallic to me. I was convinced I was going to die of a heart attack. The most frightening was that I had contracted a form of syphilis that couldn't be detected by regular lab tests. • Source • Newspapers, TV, interviews etc • Thematic analysis • Top down • Bottom up • Behavioural categories/themes emerge • Summarising • Quotes • Examples
RM o Write enough for the marks available. But don’t write too much. Answer the question. Study past questions and mark schemes. Study the report on the exam to see where students went wrong.
