Section #1 Flashcards
all material prior to exam #1
psychology experiment
1) hypothesis: testable experiment
2) identify important variables (IV and DV)
3) assign participants to groups (control and experimental) through random assignment
4) collect data
5) analyze data
6) draw conclusions
Independent variable
gets manipulated
(ex. glasses)
dependent variable
gets measured
(ex. perception of intelligence)
control group
normal, comparison, baseline, does not receive experimental treatment
experimental group
tested group (ex. glasses), receiving treatment
Random assignment
makes sure all groups are psychological equal prior to experiment
sample
portion of the whole group in a group of data
population
entire group of people in the data
nominal
Data at the nominal level serve as category names (group 1, group 2), but
do not suggest order or position in a hierarchy.
between participants
people in group 1 are not the same as those in group (one level of variable per group)
within participants
everyone experiences all levels of the independent variable (people in group 1 and 2 are the same)
ordinal
Data at the ordinal level shows rank order, or position in a hierarchy
interval
Data at the interval level also show rank order, but in this case the distance
between the numbers is meaningful.
ratio
Data at the ratio level shows order, and the “distance” between numbers is
meaningful, and zero means the total and complete absence of something
bell curve
normal
mean
bimodal curve
two bumps
mode
positive skew
left bump
median
negative skew
right bump
median
standard deviation
average distance the scores travel to get back to the mean
- measures variability
- allows us to use z-scores
why is n-1 used in the denominator of the sample estimate of the population standard deviation
because the sample under-estimates population variability, n-1 corrects this underestimation
z-score
turns raw score into standard deviation units
raw-score
original/untouched data that is not in comparable, standard deviation units
