PL1010: Research Design and Methods Flashcards
Your Deck Mentor for the Research Design and Methods deck is Bogna. You can email bogna.frykowska@forward-college.eu with any questions/suggestions about the flashcards in this deck.
Categorical variable
Variable with scores that are not on a numeric scale
Descriptive statistics –
Summarise samples – giving someone the main points in a simple form To describe data, we will use graphical and numerical (statistical) techniques
Inferential statistics –
Examine patterns in the data and consider how much data we have You can then draw conclusions about a population based on the analysis of a sample. -> conceptual replication
Summarising
collecting and summarising data
Standardisation
creating a system in which data can be assigned values (high vs low vs average)
Statistical inference
the ability to draw general conclusions from samples
How many times does a particular score occur?
Percentages/Averages Scores for a particular variable (Frequency statement)
Do scores for one variable correlate with scores for the other variable?
Statement about association
How strong is the correlation or association between two variables?
Statement about association
Do I trust that there is a “genuine” association (relationship)?
Statement about relationship between two variables
Frequency Distribution?
show scores in order and their frequency of appearance in the sample
Negatively skewed
Positively Skewed
When not to describe the skew of data?
When we cannot put our scores in order , from lowest
to highest so when we are describing a categorical
variable with unordered categories
Unimodal?
One major peak
Bimodal
Two major peaks
Approximately symmetrical
The Sample Variance formula
the n-1 leads to an unbiased estimate
How do outliers and the mean relate to each other?
Outliers are extreme values that differ from most values in the data set. Because all values are used in the calculation of the mean, an outlier can have a dramatic effect on the mean by pulling the mean away from the majority of the values.
What happens to the mean, median and mode in a skewed distribution
in normal distributions, they all take on the same number
frequency distribution
pattern of frequencies of a variable
Why are histograms good?
effective visual summary of a variable’s central tendency and variability
Why is the IQR a good measure of variability?
Because it’s not affected by outliers like the range is as it only includes the middle 50% of data?
Difference between central tendency and variability?
Central Tendency just tells you where the most important point lie while variability sums up how far apart and thus generalisable they are.