Research methods - Data handling + analysis Flashcards
What is a mean?
Mathematical average (add up all the scores and divide by the number of scores)
What is a median?
Middle value
What is a mode?
Most frequent or common value in the scores
What is a range?
The difference between the highest and lowest score.
What is standard deviation?
Measures how concentrated the data are around the mean.
What are the 3 levels of measurement?
- Nominal
- Ordinal
- Interval
What is nominal data?
- Data which is in categories
- Each participant does not have a score of their own, they are counted in categories
- All behaviour category checklists are nominal data
- All coding in a content analysis is nominal data
What is ordinal data?
- This is continuous numerical data (scale)
- All participants have an individual score
- The data is ranked numerically
- The numbers have a relationship to each other
What is interval data?
- Continuous numerical data
- This is where the difference between the numbers is the same
- There is a true mathematical meaning to the numbers
What are the characteristics of a normal distribution?
- Bell shaped
- Symmetrical (around the mean)
- Mean, median and mode all at the same mid point
What is a skewed distribution?
- “Skewed” = distorted
- What distorts the distribution is more people getting low or high values - so the data is not symmetrical - this results in the bulk of scores being on one side and a long tail on the other side
What does the distribution of a negative skew look like?
A long tail on the left.
What is a negative skew?
- A negative skew would result from a very easy test where a lot of people did well and the rarer few did badly
- But their very low scores would drag down the mean
What are the characteristics of negative skews?
- Bulk of distribution is to the right of the graph
- Long tail to the left
- Mode is at top point of curve
- Mean is pulled down to the left
- Median is in the middle of these
What does the distribution of a positive skew look like?
A long tail on the right.