Descriptive Statistis Flashcards
What are the three branches of statistics
- Descriptive statistics (organising, summarising and describing data)
- Correlational (exploring relationships)
- Inferential (generalising findings)
State what it is meant by the key term ‘variables’
Variables are measurements made within a study
What are the 4 types of variables (on the chart, in order)
- Organismic (top)
- Environmental (bottom)
- Discrete (left)
- Continuous (right)
Explain what it is meant by organismic (top) variables
Any measurement that can describe a characteristic of an organism
Explain what it is meant by environmental variables
Any measurement to describe an organisms surroundings
State 2 facts to explain what it is meant by discrete variables
- Any parameters that can only take one score
2. Can’t be sub-divided
Explain what it is meant by continuous variables
Measurements that can always be sub-divided more
State, and give an example, of all the combinations that can be made on the variable graph
- Discrete/organismic - biological sex
- Discrete/environmental - treatment used in the experiment
- Continuous/organismic - body weight
- Continuous/environmental - temperature
State, from bottom to top, the levels of measurement (LoM)
- Nominal data
- Ordinal data
- Interval data
- Ratio data
Explain nominal data (3 points)
- About identity/categories (eg - male vs female)
- Can’t infer order of magnitude
- Mutually exclusive and comprehensive
Explain ordinal data (3 points)
- Can infer order (eg - small to large)
- Don’t know the absolute magnitude of each data sample
- all the aspects of nominal data
Explain interval data (4 points) - example being shoe sizes
- Can include difference between categories
- Know the absolute score of each category
- Can’t say A is x times bigger than B
- everything in interval and nominal data
Explain ratio data (2 points) - example being 100m sprint
- Can express differences between data sets as magnitudes, percentages, fold changes, etc…
- everything in interval, ordinal and interval level data
State 2 things should should always/never do when using units
- Always - leave a space between the measurement and the unit
- Never - pluralise (add an s on) or italicise (write in italics)
State 2 positives and 1 negative of using the Mode
- Extreme outliers don’t impact
- Used with any LoM
- It’s a terminal statistic, all it shows is the mode