Flashcards in Chapter 2: Statistical Variation Deck (20):
X or Y = ??
variables that are measured...
total number of subjects or scores...
n=subsample of the sample..
N= the total sample
i can vary from 1-N......the iTH score..
N= last score in summation..
i= first score in the summation...
summation= sum of data..
Scales of measurement ?
determine types of tests used to analyze
different scales have different properties....
Properties of Measurement Scales?
Property of identity..
equal unit size...
Property of Identity ..
each value represents a descriptive category..
ex: drink brand, religious affiliation...
Property of Magnitude/ ordinality..
assigned values reflect greater than and less than...
grading scheme = ex !
Property of Equal unit size?..
difference between numbers are the same.....
ex: 120-130...and 180-190
Property of Absolute zero?
zero represents nothing of the variable...
.......# of cars in a parking lot? zero? zero= no cars....ex
Types of scales?? 4
Nominal, ordinal, interval and ratio scales...
lowest scale of measurement
deals with qualitative data not quantitative data..
property = identity
no value difference between variables....
cannot add or avg..
good for comparisons ....how many of something...
deals with data that can be ordered or ranked....
ex: olympic race..... 1st , 2nd , 3rd
there are no in between numbers..
property: identity, magnitude..
A>B B>C ... A=F
distance between ranked differences are =
Property: identity, magnitude, and interval properties..
zero is arbitrary..
can: a-b=c ..c-d...a-b>c-d..
cant do ratios no mult or divison...
Interval with true zero point....
score of zero = no amount of variable!
Property: identity, magnitude, equal interval and absolute zero!
can do all math operations...
no possible values between adjacent units...
whole numbers units or categories...
cant have 3 and a half cats!
nominal and ordinal!
can take infinite variable values in between units...
ex: drug dosage....10mg..10.1 mg...etc..
interval or ratio!
values are set at 1/2 of the scale.....
score of 72 really means 72 +/- 0.5
Upward Rounding bias?
we round up more times than we round down...