1. Type of Data Qualitative data Quantitative data
Rich in detail or description, usually in textual or narrative form, sometimes pictures
Quantitative data
Numerical data, measurements of quantity or amount

2. Type of Data Qualitative Rich in detail Allows for in-depth analysis
BUT
Difficult to analyse
Difficult to compare people or groups
Quantitative
Easier to analyse (e.g. statistically)
Easier to compare people or groups
BUT
Undetailed and potentially superficial

3. Types of data: fill in the gaps
Primary
Secondary
Meta-analysis

4. Task Answer the 4 questions
What is the difference between results and conclusion?

5. Mean Statistical or arithmetic average
+ - mean is most sensitive of all measures of central tendency, taking all scores into account
- - mean can be distorted by extreme scores (and can become unrepresentative of data)

6. Median Middle score after data is ordered
+ - unaffected by extreme scores
- - only takes 1 or 2 scores into account (middle values)

7. Mode Most frequently occurring score + - unaffected by extreme scores
- - can be affected dramatically by change in just one score (unrepresentative measure)

8. Measures of dispersion
Range – difference between highest and lowest score in a set of data; used as a simple calculation
SD – indicates ‘spread’ or dispersion of data around central value (the mean); used to show individual differences

9. Range + easy to calculate - can be affected by extreme values
doesn’t include all digits in data set

10. Standard deviation
+ more precise measure of dispersion as it takes all values into account
- extreme values may still hide some of the characteristics of the data

11. Exam question
A researcher carried out a study into the effects of a critical question on recall. The Ps watched a video of a simulated car crash and were then asked questions regarding what they had observed. In one condition the Ps were asked ‘How fast was the car going when it hit the other car?’ while in the other condition they were asked ‘How fast was the car travelling when it smashed into the other car?’ The data was then analysed.
What do the results in the table suggest about the effects of the critical question? (4 marks)
Smashed
Hit
Mean estimated speed of car
65.6mph
57.2mph SD
5.9
7.8

12. Homework
Revision notes on types of data, measures of central tendency and dispersion
Draw the graphs on page 45 and 46