Textbooks

Please return ALL CHENEY TEXTBOOKS on Tues 15th either before or after the unit 4 exam.

Thanks

Mrs Watson

Tuesday 2nd June

NO LESSON TODAY

Apologies - I am ill and at home. 

All the best for revision, any problems please send me an email. Hoping to be back in tomorrow for a final drop-in lesson.

Mrs Watson

Group displays of aggression

Today we went back to the aggression topic and filled in the remaining gap - group displays of aggression. This looks at the adaptive reasons behind aggression in the areas of sport and warfare. The reasons for aggression in these areas can largely be separated into those concerning territoriality (protection of resources) and sexual selection (aggressive group members being more likely to be sexually selected). The ppt is here.

The essay title on this topic would be something like ' Discuss one or more evolutionary explanations of group display in humans', so you should make sure that you can write this or at least construct a plan. 

Designing your own experiment

Today we started with a brief discussion of what to do when rho (the observed value in Spearman's rho) is negative, as I know this came up last week and I didn't do a very good job of clarifying the issue. Here is a simple powerpoint explaining what to do in this scenario.

We then moved on to answering the question on designing your own experiment. This often comes up and can be worth 10 or 12 marks so is worth doing well. Here is the powerpoint. We answered January 2011 Q26 in class and it would be worth doing this if you were absent. 

Wilcoxon's t-test

Today we covered the last statistical test - Wilcoxon's. This is used when the investigation has a repeated measures or matched pairs design. The worksheets to fill in are here and here and the ppt is here.

Here is a useful summary of all four statistical tests.

Here is a useful overview of the different types of data (nominal, ordinal etc). 

More statistics

Today we covered two more statistical tests - Mann-Whitney and Chi-squared. You need to know when to use each test and how to complete each test, although you would never be asked to complete a whole test. The formulae and necessary tables will always be available on the exam paper as well.

Tomorrow we will do Wilcoxon and then look at the exam questions on statistical tests.

The Mann-Whitney worksheets are here and here. The Chi-squared tests are here and here.

Probability and significance

Today we started the statistics section of the research method spec with a look at probability and significance (ppt here). Remember we always start off with a null hypothesis, with the aim being to try and disprove this and find something significant. If the probability of getting our results when the null hypothesis is true, is less than or equal to 0.05 then we say we have a significant finding and our null hypothesis can be rejected.

We then looked at our first statistical test, Spearman's rho. This is used when the data is from a correlation and when the data is ordinal or nominal. The ppt is here and the worksheets to fill in and work through are here and here.