Lesson 5 (Stats) Flashcards
Nominal Scale
catagorical, distinct categories, least complex, fewest mathmatical operations
Ex: ice cream flavors, political parties, dietary restrictions
Ordinal Scale
assigned values to data based on rank or order, second least precise scale, not proportionally spaced
Ex: Army rankings, how depressed are you?
Interval Scale
involves the use of numbers wiht equal units of measuremnts ,
ex: fahrenheit, has no true zero temp or fixed beginning, SAT scores
cannot calculate ratios between scores
Ratio Scale
equal number of units with a true zero,
weight, or Kelvin temp scale
most precise of all the scales
Descriptive Statistics
data that is representattive of a sample of the population
typically refers to reporting means, standard deviations, falls on a normal curve
Inferential Statistics
generalizing data from a sample back to a population using probabilities and hypothesis testing to make inferences about the population from a sample
Assumption of Normality
extent to which a distribution of scores approximates the standard normal curve
Assumption of Linearity
extent to which 2 variables correlate in a linear fasion, some relationships may be more curved or circular, and violate this assumption, requiring a nonparametric statistic method ot analyze the data
Assumption of Independence
scores must be independent of each other, or influencing each other in any way, Ex: pre-test post test affects each other
Assumption of Homogeneity
data differs from each other similarly Ex: F Maximum test or Levine’ test
Central Tendency
math that is used in descriptive stats
Mean
the average of all numbers: Add all numbers and divide by the number of numbers
Mode
most frequent
Range
difference between the highest and lowest scores
Median
middle point, 50% of scores above and 50% below
Calculated by adding 1 to the total number of observations and dividing by 2, if a researcher has 11 scores, the median is the 6th score when arranged from high to low, if you have an even number, take the 2 middle scores and add them together and divide by 2
Bimodal distribution
set of data that has 2 modes, important to find out why this is happening if there is a distance between the modes
homogenous distribution of scores
a distribution laking variability
varience
how close scores are to the mean
standard deviation
square root of the variance
standard bell curve distribution
this illustrates the way the scores vary around the mean by standard units
left skew distribution
Or Negative skew, mode above median (the tail is on the left) mean is to the left of the median