INVESTIGATING PSYCHOLOGY 1 – LECTURE 3 – DESCRIPTIVE STATISTICS AND
DATA VISUALISATION
DESCRIPTIVE STATS – summarise and describe data
VISUALISATION – producing graphs and plots that display data visually
INFERENTIAL STATS – tells us about the probability of the data occurring that
allow us to make inferences
HISTOGRAMS –
Display frequency distributions
Not a bar chart
Helps to find errors in data and understand distributions of data
Important for inferential stats
SKEWED DISTRIBUTIONS
Negative skews – peak shifted towards the higher numbers
Positive skews – peak shifted towards smaller numbers
Normal standard distribution – bell curve with the peak in the middle
Kurtosis –
High peak = leptokurtic
Flat distribution = platykurtic
Z SCORES –
Standardised scores – make comparisons between different scales
Z SCORES FORMULA = value – mean / SD of the set
DATA VISUALISATION
DESCRIPTIVE STATS – summarise and describe data
VISUALISATION – producing graphs and plots that display data visually
INFERENTIAL STATS – tells us about the probability of the data occurring that
allow us to make inferences
HISTOGRAMS –
Display frequency distributions
Not a bar chart
Helps to find errors in data and understand distributions of data
Important for inferential stats
SKEWED DISTRIBUTIONS
Negative skews – peak shifted towards the higher numbers
Positive skews – peak shifted towards smaller numbers
Normal standard distribution – bell curve with the peak in the middle
Kurtosis –
High peak = leptokurtic
Flat distribution = platykurtic
Z SCORES –
Standardised scores – make comparisons between different scales
Z SCORES FORMULA = value – mean / SD of the set
