Chapter 16: DESCRIPTIVE Stats Flashcards
Statistics allows you to: _______ and describe, reveal underlying ________, & make ___________
count, patterns, inferences
2 ways stats are used
- descriptive 2. inferential
What kind of stats? *make generalizations about the population (in number form) from data collected on the sample
inferential
What kind of stats? *describe the sample (demographic tables) (ex: frequencies; can be shown in pie charts)
descriptive
What is being described? *a characteristic among persons or other living things, objects, or events: eye color, hair color, temperature
variable
How can variables be described? 2 ways
- number (1=blue, 2= brown) 2. words (blue, brown, green)
Discrete or continuous variable? *takes on a finite range of values (ex: number of children in the home)
discrete
Discrete or continuous variable? *takes on infinite range of values along specified continuum (ex. age, weight, height)
continuous
Discrete or continuous variable? *AKA categorical variables
discrete
Discrete or continuous variable? used with nominal and ordinal scales
discrete
Discrete or continuous variable? *used with interval and ratio scales
continuous
T/F *continuous variables can be converted to discrete variables, but not vice versa
TRUE (ex: 1 = length less than 60 inches, 2 = length 60 inches or greater)
Name 4 levels measurement
- nominal 2. interval 3. ordinal 4. ratio (“noir” = black in French) :-)
Which level of measurement? *attributes are ordered; doesn’t tell measurable differences between levels (no equal distance between 1 and 2, ex: FIM scales)
-sorting people based on an attribute (attributes ordered according to some criteria); captures equivalence and relative rank
ordinal
(Ex. FIM scores- numbers signify incremental ability to perform ADL’s; people who score 4 on FIM are equivalent in regards to function and relative to those in other categories; does NOT tell us how much greater one level is to another)
Which level of measurement? *lowest level of measurement; mutually exclusive; no quantitative meaning to the numbers (ex: race); assigning numbers to classify characteristics into categories; provides no information other than equivalence and non-equivalence
nominal
Which level of measurement? * specify rank ordering on variable and assume equivalent distance; no real absolute magnitude (ex: age, temperature degree C and degree F–> 60 degrees is not twice as hot as 30 degrees and 0 degrees is not an absence of heat)
interval
Which level of measurement? *highest level of measurement; addresses ordering, intervals, & absolute magnitude
(ex. weight of 200lbs is twice the weight of 100lbs)
can use all arithmetic operations with this level of measurement
ratio
T/F: There is no true absence of 0 in ratio measurement.
FALSE: 0 is true absence in ratio measurement (ex: money, height, weight, minutes of time)
What type of inferential data is used with nominal and ordinal data?
non-parametric
What type of inferential stats is described? *easy to interpret, distribution free, doesn’t estimate parameters; considered less robust, and unable to handle multivariate questions
-useful when data cannot be interval level, when distribution is non-normal, or when sample size is very small
non-parametric
A continuous scale in stats tends to use which type of measurement?
interval & ratio
Which type of inferential stats uses interval & ratio measurement?
parametric
T/F: Parametric inferential stats has normal distributions, is considered more powerful, and can study multiple variables.
TRUE
What graphic describes data that cluster around a mean score or average and square root of variance?
normal curve with standard deviation
T/F: In a normal distribution, few scores are close to the mean.
FALSE: In a normal distribution, MOST scores are close to the mean, though a small number of outlier scores are significantly above or below the mean.
Positively skewed or Negatively skewed
Positively skewed
Positively skewed or Negatively skewed
Negatively skewed
Correlation, Absolute Risk, Relative risk, Relative Risk Reduction, & Odds Ratio are types of ______ stats.
Bivariate: describes relationships between 2 variables
Name the type of Bivariate stats.
*the extent to which 2 variables are related to one another
correlation
These terms will often be used in correlational studies
relationship,
association,
correlation
T/F
*correlation implies causation
FALSE
Which type of correlation:
when 1 variable increases, the other one does too
positive correlation
Which type of correlation:
when 1 variable increases, the other one decreases
negative correlation
2 widely used correlational indexes
- Pearson’s r product moment (interval or ratio data)
- Spearmen’s rho (used for ordinal level data)
Strength of correlations:
0 - .2
negligible
Strength of correlations:
.2 - .4
low
Strength of correlations:
.4 - .6
moderate
Strength of correlations:
.6 - .8
high
Strength of correlations:
.8 - 1
very high
T/F
Small sample sizes can yield higher correlations without strong effect, so be cautious about making judgment about correlation results by using significance levels only
FALSE
LARGE sample sizes can yield higher correlations without strong effect, so be cautious about making judgment about correlation results by using significance levels only
Which type of Bivariate stats?
*the proportion of people who experience an undesirable outcome in intervention and control group
Absolute Risk
Which type of Bivariate stats?
*estimated proportion of the original risk of an adverse outcome that persists among people exposed to the intervention
Relative Risk
Which type of Bivariate stats?
*the proportion of people with the adverse outcome relative to those without it
Odds Ratio
highest score minus lowest score
range
most frequently occurring score in a distribution
mode
point in distribution where 50% are above and below; does not use quantitative value of the numbers
median
sum of all scores divided by the # of scores; average
mean
Used with interval/ratio data; average amount of deviation of values from the mean and is calculated using every score; variability index for a set of scores
standard deviation
