Spearman's rho

Today we encountered our first statistical test - Spearman's rank (or rho) test for correlation.

The idiot's guide step by step worksheet is here and the second worksheet is here. The powerpoint is here.

Make sure that you complete the exam question I gave you for homework. If you carried out a Spearman's rank test in class (and you all did with the chocolate experiment) then this is above and beyond what you will need to do in the exam. The full mark scheme for the question that I gave you is here.

Probability & significance

Today we started the data analysis section of the research methods spec and spent some time discussing what we mean by probability and significance.

Using the theoretical example of whether men or women are better at map reading, and testing 50 men and 50 women, what sort of results would you need to conclude that there was a difference in map reading ability?

Average male score: 0.60 Average female score: 0.61 Null hypothesis correct

Average male score: 0.1 Average female score: 0.92 Null hypothesis rejected

Average male score 0.62 Average female score: 0.68 Is this significant???

The only way to find out is to perform a statistical test on the data. This will tell us the probability of our results occurring if the null hypothesis is true (ie if there is no difference in map reading ability). If this probability is less than 0.05 then we say that our results are significant, and that we can reject the null hypothesis.

Today's powerpoint is here. We also revised ethics and descriptive statistics from AS so do make sure you go over the relevant section in the textbook. Ethics ppt here, ethics mix and match sheet here, example information sheet and consent form here, and graphs matching activity here.

We will be going over this stuff a few times so don't worry if it bamboozles you to begin with.

Personality Factors Underlying Anomalous Experience

Today we discussed the various personality factors underlying anomalous experience, then attempted to write paragraphs evaluating any three different factors. This proved taxing, and this therefore becomes homework to be handed in next Thursday - one side of A4 if you're handwriting.

Personality Factors Underlying Anomalous Experience

Superstition and Magical Thinking

Tomorrow's test will be on this material, as well as probability judgement and coincidence:

Superstitions can be explained with behavioural ideas / learning theory and by the evolutionary approach - the link between the two (sometimes seen as opposites, as they sit on opposite sides of the nature / nurture debate) is explained by Richard Dawkins in this video about superstistious pigeons:

Superstitions are often associated with situations in which people feel out of control, and where this is stressful. Superstitious behaviour may serve a function of helping people to deal with this stress. This link describes superstitious behaviour of soldiers in Afghanistan.

Make sure you can explain this statement:

Assuming that a ‘coincidence’ (two events occurring close together in time) means that the two are causally related may have had adaptive value for our ancestors. At least, the consequences of assuming false causal links would have usually been much better than missing real causal links.

'Magical thinking' is new to the specification this year so not in most textbooks. Make sure you can define it, give examples and link to the explanations for superstitious behaviours. A key idea is that superstitions and paranormal beliefs arise from modes of thinking which are generally adaptive - that is they aid survival, at least in a world where actually understanding connections between events was usually impossible.

Here is a link to more information on Cargo Cults - a good example of magical thinking, and this site has the video clip we watched in our lesson.

Magical Thinking

Reliability & Validity

Are these rulers internally reliable? Externally reliable?

Here are the key RM terms that we've covered recently:

Reliability

Inter-observer reliability

Internal reliability

External reliability

Split-half method

Test-retest method

Internal validity

Investigator effects

Demand characteristics

Participant reactivity

Extraneous variables

Single-blind, double-blind techniques

Face validity

Concurrent validity

Predictive validity

Ecological validity

Population validity

Mundane realism

My powerpoints on reliability and validity are here and here. We'll start the stats next week, which is certainly a bit more interesting but is a bit trickier.

Research Methods

We've started the Psychological Research and Scientific Method of the Unit 4 paper. It's important that you revise the AS research methods course content to begin with, before we get onto the stats. Here's a list of resources used recently that may help:

Experimental methods big table to fill in

Experimental design ppt using Peterson & Peterson (1959) as an example

Mini sheet on experimental design

Sampling techniques ppt

Article from The Psychologist on the use of student participants in Psychological research

AS and A2 Psychology specification

Enjoy.....

Superstition, Coincidence and Probability Judgement

We have moved on to 'Explanations for Anomalistic Experience' - the middle section of the specification. Here is what you need to know:

• The role of coincidence and probability judgements in anomalous experience 
• Explanations for superstitious behaviour and magical thinking 
• Personality factors underlying anomalous experience

There are a couple of changes from last year's specification - mainly things being taken out, but 'magical thinking' is new and 'probability judgements' have become more important. Bear in mind that textbooks which were published more than a year ago are therefore a bit out of date.

Here are the updated 'dog book' pages for the changed parts of the Anomalistic topic. We were looking at the 'Coincidence and probability judgements' double-page-spread yesterday and you need to answer the questions at the end of this for next Thursday (at the bottom of page 3 of the pdf).
Here is the presentation we used in Monday's lesson:

Today we looked back at research on PK and ESP and discussed the following questions:

1. What examples have we looked at of scientific fraud? Why have these happened and what is their impact on the status of parapsychology? 
2. What methodological issues have affected the validity of research into ESP and psychokinesis? 
3. What investigator effects are evident in this research? Why are these such a big issue? 
4. What is ‘publication bias’ and why is it such a big issue?

We then looked ahead to the next section - the specification has changed a bit this year, here is the new wording:

Explanations for anomalous experience:

• The role of coincidence and probability judgements in anomalous experience 
• Explanations for superstitious behaviour and magical thinking 
• Personality factors underlying anomalous experience

Homework for Tuesday (bring answers, note form fine):

1. What personality factors have been found to relate to anomalistic experience? 
2. What has research found about a link between probability judgement and anomalous belief?