STATS T1 Flashcards
(57 cards)
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
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
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
Why are histograms good?
effective visual summary of a variable’s central tendency and variability
What is a discrete, continuous, independent and dependent variable?
Discrete: variable that is limited (age, gender) Continuous: exists on a continuum basically infinite between highest/lowest IV: variable manipulated/changed to see whether it has an effect on the DV that might change because of the manipulation DV: variable that, though measured, is not being controlled
What is the role of measurement scales?
The numbers don’t necessarily say anything concrete about the objects measured <i>ex.: if I scored high on a test, but someone else scored lower, it’s not necessary because they remembered less even though the data might suggest it → we assume that they mean I remembered more</i>
What is the purpose of a frequency distribution?
Organising data into a meaningful order of how many times
Which variable do I usually find on the X- and Y-Axis in histograms vs. line graphs?
histogram: dv-iv Line/Bar graph: iv-dv
What is the mode, median, mean (+formulas)?
Mode: the highest point in the graph Median: 50th percentileMean: Sum of N/ N
