using ststats to answer questions Flashcards
what are predictions based off of?
correlation coefficient
correlation coefficient:
single number representing the degree of relation between two variables
Pearson product- moment correlation coefficient is appropriate for:
interval or ratio scales of measurement
the interval or ratio scales of measurement ranges from:
-1.00 and +1.00
coefficient tells you both:
magnitude and direction of relationship
perfect positive correlation:
as the scores of one variable increase, the scores of the other variable of interest increase correspondingly and proportionally
zero correlation:
as the scores of one variable of interest increase, scores of the second variable either increase, decrease, or stay the same. no prediction possible
perfect negative correlation:
as the scores of the first variable of interest increase, scores of the second variable correspondingly and proportionally decrease
significant:
results would occur rarely due to chance alone. therefore like due to the manipulation of the IV
what does it mean to infer things about the population and sample?
do significance testing
null hypothesis of example of gamer status and number of pairs of shoes:
the mean number of pairs of shoes owned by gamers DOES NOT DIFFER from the mean owned by non-gamers
experimental hypothesis of example of gamer status and number of pairs of shoes:
the mean number of shoes owned by gamers DIFFERS from that owned by non gamers
T-Test (difference between means):
used to evaluate the difference between 2 groups
experimental hypothesis can be
directional or non directional
two tailed:
probability of the result occurring by chance alone is split in half and distributed equally to the two tails of the distribution
