L2 - Descriptive data analysis and hypothesis development Flashcards
Difference between isomorph and homomorph mapping of the world
Draw levels of measuremnt of the variable
what is mode
most frequent value
For which levels of measurement can the mode be applied?
all of them
For which level of measurement can median be applied
at least ordinal
for which level of measurement can mean be applied
at least interval scale
What is more informative for a skewed distribution? Median or Mean?
Median
If you have a left/negatively skewed distribution then is the mean or median higher?
median is higher
In a right-skewed distribution the X is typically higher than the Y
mean is higher than median
Range at least which scale?
ordinal
IQR which scale at least?
ordinal
variance at least which scale?
interval
What is Kurtosis
Peakedness
What is y = 0 (Kurtosis measure)
normal distribution
y > 0
peaked distribution
Skewness measure
gm
What if gm > 0:
right-skewed
How does kurtosis: 1.77 and skew 1.4 look like?
What are 3 measures of association between two variables?
- Product-moment correlation (Pearson)
- Rank correlation (Spearman)
- Cramer’s V
What is the range for pearson?
-1 to 1
Wat is spearman range?
-1 to 1
range for Cramer’s V
0 to 1
What is a Cramer’s V of 0?
No association (1 is perfect association)
Are the minimal scale requirements the same for person and spearman?
No. Pearson needs at least interval and Spearman at least ordinal.
When is Cramer’s V used
both variables are nominal
If there are outliers then is the rank correlation or person more robust?
Spearman is more robust
What is induction?
from specific to general
What is deduction
from general to specific
What is general validity?
If it goes beyond a single case
two main aspects of a good scientific hypothesis?
- Falsifiability
- Empricial context
What is falsifiability about?
- Variables must be observable
- existential hypothesis are problematic (something “can” happen)
