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

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

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

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

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)

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

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

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

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

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

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

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