1. Up to 33% of total A level from Research Methods and Statistics
Lesson 4
Research Methods and Statistics
- Unit 2 –
Also questions in Unit 1 & 3
Up to 33% of total A level from Research Methods and Statistics
10% of total A level from applying maths skills

2. Prep for lesson 5
Go to the ‘first two weeks 2018’ on psych205 and complete the ‘prep for lesson 5’ work for next lesson. Also…..

3. …. The Mathematics test
You completed some mathematics homework over the summer Go to the VLE and click on the Icon on the year 1 psychology section. Once you agree to start this, you only have 30 minutes to complete it. The results will be logged and there will be a formal record of this attempt with your score. It is open now, and the deadline to complete this is 3.45pm on Wednesday 26th September Please note that the answers are very sensitive. Like the exam, if you forget to put a % after an answer asking for percentages, you will not receive a mark. Similar, watch out for advice on decimal places. Good luck.

4. Analysis of the experiment
We are going to analyse our experiment today by…
Collation of data
Analysis of data
Analysis of further patterns in data
Can we support or reject the hypothesis
Conclusions – does this support or refute informational social influence as a theory?
Criticism of our experiment in terms of validity, sample technique, research design

5. Changed Answer on Question 4
Data Analysis
Please have your data in front of you
We are going to fill in this 2x2 contingency table (2x2 contingency table: it’s what this type of table is called).
But first, can you think of a title for this table (all tables must have a well described title)
Changed Answer on Question 4
Did Not Change Answer
On Question 4
Quiet reflection
Group estimate sheet

6. Changed Answer on Question 4
Data Analysis
2x2 contingency table showing how many participants did or did not change their estimates on a question about road length depending on weather they were exposed to group estimates or not
The AQA exam board want students to give detailed titles to tables and graphs
Changed Answer on Question 4
Did Not Change Answer
On Question 4
Quiet reflection
Group estimate sheet
Such a common mistake. Please write ‘whether’

7. Changed Answer on Question 4
Data Analysis
Lets collate the data: put your hand up if the cell applies to your participants (you should only put your hand up twice)
2x2 contingency table showing how many participants did or did not change their estimates on a question about road length depending on whether they were exposed to group estimates or not
Changed Answer on Question 4
Did Nott Change Answer
On Question 4
Quiet reflection
Group estimate sheet

8. Now convert these scores into percentages Changed Answer on Question 4
Data Analysis
Now convert these scores into percentages
Click for hint on how to do this
Cell score / total of all scores x 100
2x2 contingency table showing the percentage of participants who did or did not change their estimates on a question about road length depending on whether they were exposed to group estimates or not
Changed Answer on Question 4
Did Nott Change Answer
On Question 4
Quiet reflection
Group estimate sheet

9. Now convert the actual scores into a bar chart
Data Analysis
Now convert the actual scores into a bar chart
Detailed title: A bar chart showing the number of participants who did or did not change their estimates on a question about road length depending on whether they were exposed to group estimates or not
Why would we use a bar chart with this data?
Discrete data (in categories)
Should the bars be separate or next to each other?
Separate
Should number of participants be on X or Y axis?
Y axis
Should the first bar be right next to the Y axis or a little distant apart?
Apart
Should you include a key?
Depends on how well you have labelled your X axis

10. An example of what a bar chart should look like
A bar chart showing the number of participants who did or did not change their estimates on a question about road length depending on whether they were exposed to group estimates or not

11. Analysis of the Results
Given these findings, do you think we have an experimental effect? What should we do about our experimental hypothesis? support it or reject it. Why? Does our study support the theory of informational social influence? Why/why not?

12. Null and Alternative Hypothesis
The null hypothesis: If the experiment does not have an effect, then both groups will have a similar number of people who have changed their answer. If this is the case, we would support a null hypothesis. Simply speaking “Nothing has changed”. The alternative to this is that there is an experimental effect and that “Something has changed”. This is known as the alternative hypothesis (sometimes called the experimental hypothesis) In an experiment, a psychologist will predict both a null hypothesis and an alternative hypothesis. Complex statistical analysis (see year 2) allows psychologists to support one or the other with a certain level of probability. More of that as the course progresses.

13. Hypothesis recap
Hypotheses are statements that predict the outcome of an experiment.
Hypotheses
Experimental
Directional
Non-directional
Null
Predicts that there won’t be a difference between groups.
Predicts which group (condition) of scores will be larger than the other.
Used when there is strong evidence from previous research
Predicts there will be a difference in scores (conditions) but not which group will be larger?
Used when there is no previous research.

14. So which hypothesis should be supported?
Null Hypothesis: There will be no difference in the number of participants who have changed their answer on a question about road lengths between those who have been given a group estimate during reflection, and those who were given no information during reflection
Alternative Hypothesis: Participants given a group estimate to a question about road length are more likely to change an initial answer than participants who are given no group estimates to the question on road lengths.

15. Further analysis
Sometimes its interesting to see if there are differences between certain groups Collate the data for males and females and convert into percentages. Any interesting findings? Collate the data for different age brackets and convert into percentages. Any interesting findings?

16. Critical Analysis
A vital part of scientific enquiry is the critical analysis of each experiment. There maybe questions with the design of the experiment, the running of the experiment, even the statistical analysis of the data which means that psychologists make weak or even false conclusions
Task: On the BWBs, write as many flaws in the study as you can think of and why you think it is a flaw.
Do not hold back with this, it is an important part of scientific investigation, so stick the boot in!
Example: The participants were tested in different environments. This means that there we cannot tell if the participants’ behaviour was influenced by their unique environment rather than the experimental conditions

17. Populations and Sampling
Researchers cannot study all humans (7 billion)
Researchers have to consider what their ‘target’ population is.
This is sometimes determined by a specific grouping that researchers wish to know about (e.g. All people living in Brighton and Hove between the ages of 16 to 18).
Usually, researchers cannot study all the target population either, so they will take a sample from that target population
Its best to get a sample that is representative of the target population. In reality, this is very challenging and is rarely achieved.
This leads to a biased sample, which then limits conclusions about the study.

18. The Sampling Method Stratified Opportunity Random Systematic Volunteer
With Psychology A level, the use of 5 sampling techniques are considered. Decide which definition matches the terminology. A) All people within a target population have an equal chance of being selected B) Participants have responded to a request to take part in an investigation, for example, they have seen an advert in a magazine C) The researchers choose the nth person from the target population D) The researcher decides on categories (strata) that are really important to be represented in the sample. Once the strata are established, participants are randomly selected from each strata. The proportion of the sample within each strata must mirror that of the total target population E) A researcher will use anyone who is available (and agrees to take part) at that given moment
Stratified
Opportunity
Random
Systematic
Volunteer

19. Answers
Identify which sampling method goes with these definitions A) = Random: All people within a target population have an equal chance of being selected B) = Volunteer: Participants have responded to a request to take part in an investigation, for example, they have seen an advert in a magazine C) = Systematic: The researchers choose the nth person from the target population D) = Stratified: The researcher decides on categories (strata) that are really important to be represented in the sample. Once the strata are established, participants are randomly selected from each strata from the target population. The proportion of the sample within each strata must mirror that of the total target population E) = Opportunity: A researcher will use anyone who is available (and agrees to take part) at that given moment

20. Prep for lesson 5: Complete similar notes for all 5 sampling techniques using pages in the information pack on psych205

21. Examples – on MWBs on your own
Identify which of these examples go with which sampling technique (just write the words in bold for speed)
A criminologist chose every 10th prisoner at Ford prison from the register in alphabetical order for a study on the treatment of prisoners in an open prison
A social psychologist chose 14 broad categories of ethnicity and randomly assigned the correct proportion relative to the population of Brighton and Hove to each category
Neurobiologists advertised in a health magazine for participants to help with an experiment into sleep deprivation
A second year BHASVIC psychology student was allowed access to the complete BHASVIC student register. They assigned a number to each name, and selected 50 numbers using a computer with random number generating software, and choose a sample of 50 students
A social psychology post-graduate asked his students if they would take part in a study on memory

22. Examples - MWBs Answers
Volunteer: Neurobiologists advertised in a health magazine for participants to help with an experiment into sleep deprivation
Systematic
A criminologist chose every 10th prisoner at Ford prison from the register in alphabetical order for a study on the treatment of prisoners in an open prison
Stratified: A social psychologist chose 14 broad categories of ethnicity and randomly assigned the correct proportion relative to the population of Brighton and Hove to each category
Random: A second year BHASVIC psychology student was allowed access to the complete BHASVIC student register. They assigned a number to each name, and selected 50 numbers using a computer with random number generating software, and choose a sample of 50 students
Opportunity: A social psychology post-graduate asked his students if they would take part in a study on memory

23. Your experiment
Which sampling method did we use for our experiment? Opportunity sample Identify one advantage and disadvantage of this sampling method (use pages in information pack if required) How might this affect the conclusions of your experiment?

24. Prep for lesson 5 There is a lot to do for lesson 5
Sampling homework (see previously)
Definitions of
Internal and external validity
Reliability
Experimental design